Tomoya Enokido

Tomoya Enokido
Rissho University · Faculty of Business Administration

PhD

About

563
Publications
16,896
Reads
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4,559
Citations
Citations since 2016
210 Research Items
2740 Citations
20162017201820192020202120220100200300400500600
20162017201820192020202120220100200300400500600
20162017201820192020202120220100200300400500600
20162017201820192020202120220100200300400500600

Publications

Publications (563)
Chapter
It is critical to reduce the energy consumption of information systems to realize green societies. The IoT (Internet of Things) is so scalable that millions to billions of computers and devices are interconnected in types of networks and accordingly huge amount of energy is consumed. In our previous studies, the TBFC (Tree-Based Fog Computing) mode...
Chapter
The MVCC (Multi-Version Concurrency Control) is so far proposed to increase the concurrency of multiple conflicting transactions and the scalability of a distributed system. However, the larger number of transactions are concurrently performed, the larger amount of electric energy is consumed by servers in a system. In our previous studies, the EEM...
Chapter
In the IoT (Internet of Things), data are exchanged among subjects and objects in devices through manipulating objects. Even if subjects manipulate objects in accordance with the CBAC (Capability-Based Access Control) model, the subjects can get data which are not allowed to be gotten by the subjects, i.e. illegal information flow and late informat...
Chapter
It is critical to reduce the electric energy consumption of information systems to realize green societies. Here, each server has to negotiate with other servers to decide on which virtual machine to migrate to and from which servers. In this paper, we newly propose an NM (Negotiation for Migration of virtual machines) protocol for servers to negot...
Article
In current information systems, a huge number of IoT (Internet of Things) devices are interconnected with various kinds of networks like WiFi and 5G networks. A large volume of data is gathered into servers from a huge number of IoT devices and is manipulated to provide application services. Gathered data is encapsulated along with methods to manip...
Article
The IoT (Internet of Things) is now one of the most significant infrastructure and has to be secure against malicious accesses. Especially, it is critical to make devices secure in the IoT. In the CBAC (Capability-Based Access Control) model adopted to the IoT, device owners issue subjects capability tokens, i.e. a set of access rights on objects i...
Chapter
It is critical to reduce the electric energy consumption of information systems to realize green societies. In this paper, we discuss the migration approach to reducing the energy consumption of servers by taking advantage of live migration technologies of virtual machines. We propose a VM (Virtual machine Migration) algorithm to make virtual machi...
Chapter
In object-based systems, applications are composed of multiple objects and transactions created on clients issue methods to manipulate the objects. Multiple conflicting transactions have to be serialize to keep all the objects mutually consistent. If the more number of transactions are concurrently performed in a system, the throughput of a system...
Chapter
In the IoT (Internet of Things), data are exchanged among subjects and objects in devices through manipulating objects. Here, even if subjects manipulate objects according to the CBAC (Capability-Based Access Control) model, the subjects can get data which the subjects are not allowed to get, i.e. illegal information flow and late information flow...
Chapter
It is critical to reduce the energy consumption of clusters of servers. Through virtual machines, applications can take advantage of virtual services independent of heterogeneity and locations of servers. Here, we have to select a host server and a virtual machine on the server to perform an application process so that the total energy consumption...
Chapter
Process replication approaches using a server cluster system are widely used to provide reliable and available distributed application services. However, a server cluster system consumes a large amount of electric energy compared with process non-replication approaches. In this paper, an RATB-DSTPR (Redundant Active Time-Based algorithm with Differ...
Chapter
In the CBAC (Capability-Based Access Control) model for the IoT (Internet of Things), subjects are issued capability tokens, i.e. a set of access rights on objects in devices, by device owners. Objects are data resource in a device which are used to store sensor data and action data. Through manipulating objects of devices, data are exchanged among...
Chapter
In the CBAC (Capability-Based Access Control) model to make the IoT (Internet of Things) secure, subjects are issued capability tokens, i.e. a set of access rights on objects in devices, by device owners. Objects are data resource in a device which are used to store sensor data and action data. Through manipulating objects of devices, data are exch...
Chapter
Applications can take advantage of virtual computation services independently of heterogeneity and locations of servers by using virtual machines in clusters. Here, a virtual machine on an energy-efficient host server has to be selected to perform an application process. In this paper, we propose an SMI (Simple MI) algorithm to estimate the energy...
Chapter
The Blockchain is now used in various applications like Bitcoin. Here, a database named ledger is fully replicated on every node, which is a chain of blocks. Each block is composed of transactions and is appended to the ledger at each node. Nodes may tamper with transactions, i.e. nodes suffer from Byzantine faults. Consensus protocols tolerant to...
Chapter
In server cluster systems like cloud computing systems, process replication approaches are widely used to provide available and reliable distributed application services. However, process replication approaches imply the large amount of electric energy consumption than non-replication approaches. In this paper, an RATB-DSTFMRT (Redundant Active Tim...
Chapter
It is critical to reduce the electric energy consumption of information systems to realize green societies. In this paper, we take the live virtual machine migration approach to reducing the energy consumption of servers. In our previous studies, each server is assumed to be able to obtain the local state of every other server like the number of ac...
Chapter
In current information systems like the IoT, a huge volume of data is gathered from various types of devices and is encapsulated along with methods as an object. An application is composed of multiple objects allocated to servers. Multiple conflicting transactions issued by clients have to be serialized to keep every object mutually consistent. How...
Chapter
In the IoT (Internet of Things), objects in devices are manipulated by subjects. Here, data are exchanged among subjects and objects. Even if subjects manipulate objects according to the CBAC (Capability-Based Access Control) model, the subjects can get data which the subjects are not allowed to get, i.e. illegal information flow and late informati...
Chapter
The MVCC (Multi-Version Concurrency Control) is proposed to increase the concurrency of multiple conflicting transactions and the scalability of a distributed computing system. On the other hand, the larger number of transactions are concurrently performed in a system, the larger amount of electric energy is consumed on servers. In this paper, the...
Chapter
In server cluster systems, process replication approaches are widely used to provide reliable and available distributed application services. However, in process replication approaches, a large amount of electric energy is consumed by a server cluster since multiple replicas of each application process are performed on multiple virtual machines in...
Chapter
It is critical to reduce the electric energy consumption of information systems, especially clusters of servers. In order to reduce the energy consumption, we have to select a virtual machine on an energy-efficient server to perform an application process so that total energy consumption of servers can be reduced. Here, we have to estimate how much...
Chapter
The CBAC (Capability-Based Access Control) model where device owners issue subjects capability tokens, i.e., a set of access rights on objects in devices, is adopted to the IoT (Internet of Things). Objects are data resource in a device which are used to store sensor data and action data. A subject sbi can get data of an object omk in a device dk b...
Chapter
Reliable and available distributed application services can be provided by redundantly performing each application process. However, multiple replicas of each application process are performed on multiple virtual machines in a server cluster system. As a result, a server cluster consumes a large amount of electric energy to provide application serv...
Article
In the fog computing (FC) models, a fog node supports not only routing functions but also application processes. By the application processes, output data are calculated on input data from sensors and other nodes and sent to target fog nodes which can calculate on the output data. In this article, we consider the mobile topic‐based publish/subscrib...
Article
In the CBAC (Capability-Based Access Control) model proposed for realizing the secure IoT (Internet of Things), authorizers issue subjects capability tokens, i.e. sets of access rights on objects in devices. Objects are data resources which are used to store sensor data and action data. Data of an object may be stored in another object through comm...
Article
In the Internet of Things, the CBAC (capability‐based access control) model is proposed to make devices securely accessed. Here, an owner of a device issues a capability token, that is, a set of access rights, to a subject. The subject is allowed to manipulate ROs (resource objects) in the device according to access rights in the capability token....
Chapter
Full-text available
Process replication can provide reliable and available distributed application services. On the other hand, a large amount of electric energy is consumed to provide replicated processes since multiple replicas of each application process have to be performed on multiple virtual machines in a server cluster system like cloud computing systems. In th...
Chapter
In the CBAC (Capability-Based Access Control) model proposed for the IoT (Internet of Things), authorizers, e.g. device owners, issue capability tokens, i.e. a set of access rights on resource objects in devices, to subjects. Since data of a device are stored in another device through communication among subjects and devices, a subject sb can get d...
Chapter
Full-text available
In order to provide scalable and high performance distributed application services, an energy-efficient server cluster system equipped with virtual machines like cloud computing systems are required. Here, processing load of virtual machines has to balance with one another to not only achieve performance objectives but also reduce the total electri...
Chapter
Full-text available
The IoT (Internet of Things) consumes huge amount of electric energy since millions to billions of device nodes are interconnected. In order to decrease the energy consumption of the IoT, the TBFC (Tree-based Fog Computing) model is proposed in our previous studies. Here, fog nodes are hierarchically structured where a root node shows a cloud of se...
Chapter
Full-text available
In the fog computing (FC) models, a fog node supports not only routing functions but also application processes. By the application processes, output data is calculated on input data from sensors and other fog nodes and sent to target fog nodes which can calculate on the output data. In this paper, we consider the MPSFC (Mobile topic-based PS (publ...
Chapter
Full-text available
We have to decrease electric energy consumption of information systems, especially servers to realize green societies. Information systems are composed of servers. One server is selected to perform an application process issued by a client so as to not only increase the performance but also reduce the energy consumption of the servers. In our previ...
Chapter
Full-text available
In the IoT (Internet of Things), the CBAC (Capability-Based Access Control) model is proposed to make sensor and actuator devices secure. Here, an owner of a device issues a capability token, i.e. a set of access rights to a subject. The subject is then allowed to manipulate resource objects in the device according to the access rights in the capab...
Chapter
Full-text available
It is critical to reduce electric energy consumed in information systems, especially servers in clusters to realize green society. By making a virtual machine migrate from a host server to a guest server, the energy consumption of the host server can be reduced since application processes on the virtual machine leave the host server. On the other h...
Chapter
Full-text available
Wireless ad-hoc networks are getting more important in various applications like V2V (vehicle-to-vehicle) networks and opportunistic networks. Here, it is critical to reduce the electric energy consumption of nodes in networks. Each node consumes more energy to perform software processes to send and receive messages than the wireless communication...
Chapter
Full-text available
In order to reduce the traffic of networks and servers in the IoT, types of the fog computing (FC) models are proposed, which are composed of fog nodes. A fog node supports application processes to calculate output data on sensor data and forward the output data to servers. A topic-based PS (publish/subscribe) model is a new contents-aware, event-d...
Chapter
Full-text available
In object-based information systems, an application is composed of multiple objects and each object is replicated on multiple virtual machines installed in multiple physical servers to make an application service reliable and available. On the other hand, the total amount of electric energy consumed in physical servers is larger than non-replicatio...
Chapter
Full-text available
In order to make a system tolerant of faults, an application process is replicated on multiple servers. Application processes more easily get faulty due to bugs and security attacks like virus than servers according to the advances of hard- ware and architecture technologies. Even if a replica sends a proper reply, the replica may not do proper com...
Chapter
Full-text available
In communication among nodes in areas struck by disaster like earthquakes and V2V (vehicle-to-vehicle) communication, each node communicates with other nodes in infrastructure-less networks like wireless networks. Here, a node has to keep messages in the buffer until some node comes in the communication range. Thus, a node has to wait for opportuni...
Chapter
Full-text available
It is critical to reduce electric energy consumption of information systems, especially servers in clusters to reduce carbon dioxide emission. First, a client issues an application process to a cluster and one server is selected to perform the process, where the energy consumption is smallest in the cluster. In addition, we take a migration approac...
Chapter
Full-text available
Distributed applications are composed of various types of objects which are encapsulations of data and methods to manipulate the data in the objects. In order to provide reliable and available application services, each object is replicated on multiple virtual machines in a system. On the other hand, a system consumes a large amount of electric ene...
Chapter
Full-text available
In order to efficiently realize the IoT, the fog computing (FC) models are proposed, which are composed of fog nodes. A fog node supports application processes to calculate output data on input data from sensor and other fog nodes and sends the output data to fog nodes which can calculate on the output data. In this paper, we consider the MPSFC (Mo...
Chapter
Full-text available
In the fog computing model to realize the IoT, each fog node supports application processes to calculate output data on input data received from a fog node and sends the output data to a fog node. In our previous studies, types of the TBFC (Tree-Based Fog Computing) models are proposed to reduce the electric energy consumption and execution time of...
Chapter
Full-text available
We have to decrease electric energy consumption of information systems, especially servers to reduce carbon dioxide emission. In information systems, a client issues application processes to servers in clusters. Application processes have to be performed on servers so that the total energy consumption of servers in the cluster can be reduced. In th...
Chapter
Full-text available
In order to decrease the energy consumption of the IoT (Internet of Things), the TBFC (Tree-based Fog Computing) model is proposed in our previous studies. Here, fog nodes are hierarchically structured where a root node shows a cluster of servers and a leaf node indicates an edge node which communicates with sensors and actuators. Each fog node sup...
Chapter
Full-text available
In order to realize various types of distributed application services, various kinds of data are gathered from various types of devices. Each gathered data unit is stored in an object like database systems. Each object is replicated on multiple virtual machines in a system to provide reliable and available application services. However, a large mou...
Chapter
Full-text available
In the fog computing model to realize the IoT, each fog node supports application processes to calculate output data on input data received from a fog node and sends the output data to another fog node. In our previous studies, types of the TBFC (Tree-Based Fog Computing) models are proposed to reduce the electric energy consumption and execution t...
Chapter
Full-text available
In disaster-tolerant (DTN) and vehicle-to-vehicle (V2V) networks, each node communicates with other nodes in infrastructure-less networks using wireless networks. Here, a node has to wait for opportunity that the node can communicate with another node. Even if a message is successfully forwarded to a neighboring node, the node might be unable to fo...
Chapter
Full-text available
We have to decrease electric energy consumption of information systems, especially servers to reduce carbon dioxide emission. In this paper, we discuss how to select a server to perform a new application process issued by a client so as to reduce the total energy consumption of servers in a cluster. Here, we have to estimate the execution time of a...
Book
This book explores three interwoven and challenging areas of research and development for future ICT-enabled applications: software intensive systems, complex systems and intelligent systems. Software intensive systems are systems that extensively interact with other systems, sensors, actuators, devices and users. More and more domains are now emp...
Book
This book aims to provide the latest research findings, innovative research results, methods, and development techniques from both theoretical and practical perspectives related to the emerging areas of information networking and their applications. The networks and information systems of today are evolving rapidly. There are new trends and applica...
Book
This book aims to provide the latest research findings, innovative research results, methods and development techniques from both theoretical and practical perspectives related to the emerging areas of broadband and wireless computing. Information networks of today are going through a rapid evolution. Different kinds of networks with different char...
Book
This book presents original contributions to the theories and practices of emerging Internet, data and web technologies and their applicability in businesses, engineering and academia. The Internet has become the most proliferative platform for emerging large-scale computing paradigms. Among these, data and web technologies are two most prominent p...
Book
This book covers the theory, design and applications of computer networks, distributed computing and information systems. Networks of today are going through a rapid evolution, and there are many emerging areas of information networking and their applications. Heterogeneous networking supported by recent technological advances in low-power wireless...
Book
This book includes the proceedings of the 15th International Conference on Complex, Intelligent, and Software Intensive Systems, which took place in Asan, Korea, on July 1–3, 2021. Software intensive systems are systems, which heavily interact with other systems, sensors, actuators, devices, and other software systems and users. More and more domai...
Article
Full-text available
In the Fog Comput$ing (FC) model of the Internet of Things (IoT), application processes to handle sensor data are distributed to fog nodes and servers. In the Tree-based FC (TBFC) model proposed by the authors, fog nodes are hierarchically structured. In this article, the authors propose a TBFC for a General Process (TBFCG) model to recover from th...
Chapter
Full-text available
It is critical to reduce electric energy consumed by servers in clusters to reduce carbon dioxide emission. Here, application processes issued by clients are performed on servers in clusters. In this paper, we take the migration approach that application processes on a server migrate to a guest server by using the live migration technologies of vir...
Chapter
Full-text available
In the fog computing (FC) models, a fog node supports application processes to calculate output data on input data from sensors and other fog nodes and sends the output data to target fog nodes which can calculate on the output data. In this paper, we consider the MPSFC (Mobile topic-based PS (publish/subscribe) FC) model where mobile fog nodes com...
Article
Current information services are constructed by new technologies like intelligent Edge, Fog and Internet of Things (IoT)-based computing and networking. The intersection of these research areas with artificial intelligence (AI) is an extremely important topic and an area of very high research interest in the research community. With the formalizati...
Article
Full-text available
The Internet of Things is composed of sensor and actuator devices. Devices have to be securely accessed by subjects. In this article, we take the capability‐based access control (CBAC) model where a subject is issued a capability token to manipulate a device by a device owner. In the CBAC model, information which a subject is not allowed to get may...
Chapter
Full-text available
In information systems, each application data is replicated to multiple virtual machines installed in multiple physical servers to realize reliable and available application services. While reliable and available application services can be provided by data replication schemes, a larger amount of electric energy is consumed in a system than non-rep...
Chapter
Full-text available
Fog Computing models are discussed to efficiently realize the IoT (Internet of Thing). In our previous studies, types of the TBFC (Tree-Based Fog Computing) models are proposed to reduce the electric energy consumption and execution time of fog nodes and servers to make it fault-tolerant. Here, fog nodes support application processes to calculate o...
Chapter
Full-text available
In order to reduce the traffic of networks and servers in the IoT, types of the fog computing (FC) models are proposed, which are composed of fog nodes which support application processes to calculate output data on sensor data and forward the output data to servers. A topic-based PS (publish/subscribe) model is a new contents-aware, event-driven m...
Article
Full-text available
In object based systems, an object is an unit of computation resource. Distributed applications are composed of multiple objects. Objects in an application are replicated to multiple servers in order to increase reliability, availability, and performance. On the other hand, the large amount of electric energy is consumed in a system compared with n...
Article
There are various kinds of Internet of Things (IoT) services like home management services. In the IoT services, a large volume of data is gathered from various types of smart devices and is manipulated in scalable, high performance, and fault-tolerant computing systems like cloud computing systems. Reliable and available IoT services can be provid...
Chapter
Full-text available
In order to increase the performance of the IoT (Internet of Things), types of the FC (Fog Computing) models are proposed. Here, subprocesses of an application process to handle sensor data are performed on fog nodes in addition to servers. Fog nodes are hierarchically structured where a root node shows a cluster of servers and a leaf node indicate...
Chapter
Full-text available
Multiple replicas of each application process can be redundantly performed on multiple virtual machines in a server cluster system to realize reliable application services. However, a large amount of electric energy is consumed in a server cluster since multiple replicas of each application process are performed on multiple virtual machines. In thi...
Chapter
Full-text available
In the IoT (Internet of Things), the CapBAC (Capability-Based Access Control) model is proposed to make devices secure. Here, an owner of a device issues a capability token, i.e. a set of access rights to a subject. The subject is allowed to manipulate the device according to the access rights authorized in the capability token. In the CapBAC model...
Chapter
Full-text available
In this paper, we discuss the mobile fog computing (MFC) model including mobile fog nodes which communicate with other fog nodes in wireless networks. Here, each fog node supports some process by which output data is obtained by processing input data received from other fog nodes and sensor nodes and sends the output data to target fog nodes which...
Chapter
In our previous studies, the TBFC (Tree-Based Fog Computing) model of the IoT is proposed to reduce the electric energy consumed by fog nodes and servers. Here, fog nodes are hierarchically structured in a height-balanced tree. A root node shows a cloud of servers and leaf nodes indicate edge fog nodes which communicate with sensors and actuators....
Chapter
Full-text available
Wireless ad-hoc networks are getting more important in various applications like (vehicle-to-vehicle) V2V networks and opportunistic networks. Here, it is critical to reduce the electric energy consumption of nodes in networks. Each node consumes more energy to perform software processes to send and receive messages than the wireless communication...
Chapter
In the P2PPS (P2P (peer-to-peer) type of a topic-based PS (publish/subscribe)) model, each peer can be a subscriber and publisher. Peers publishes messages to communicate with other peers. Here, messages are characterized by topics. Messages which have a common topic are considered to be related. In our previous studies, a hierarchical group model...
Chapter
Full-text available
In topic-based publish/subscribe (PS) model, each peer process (peer) only receives an event message whose publication topics include some common topic with the subscription topics. In a P2PPSO (P2P (peer-to-peer) type of topic-based PS with Object concept) model, each peer exchanges objects by publishing and receiving event messages with no centra...
Chapter
Full-text available
In order to reduce the traffic of networks and servers, the fog computing model is proposed to realize the IoT (Internet of Things). In our previous studies, the fault-tolerant tree-based fog computing (FTBFC) model is proposed to be tolerant of faults of fog nodes. If a fog node \(f_{j}\) is faulty, child fog nodes of \(f_{j}\) are disconnected. A...