Peer-to-peer (P2P) technology has gained popularity as a way to enhance system performance. Nodes... more Peer-to-peer (P2P) technology has gained popularity as a way to enhance system performance. Nodes in a P2P network work together by providing network resources to one another. In this study, we examine the use of P2P technology for video streaming and develop a distributed incentive mechanism to prevent free-riding. Our proposed solution combines WebTorrent and the Solana blockchain and can be accessed through a web browser. To incentivize uploads, some of the received video chunks are encrypted using AES. Smart contracts on the blockchain are used for third-party verification of uploads and for managing access to the video content. Experimental results on a test network showed that our system can encrypt and decrypt chunks in about 1/40th the time it takes using WebRTC, without affecting the quality of video streaming. Smart contracts were also found to quickly verify uploads in about 860 milliseconds. The paper also explores how to effectively reward virtual points for uploads.
On Linkage Identification in EC for Solving Combinatorial Optimization Problems
2005 IEEE International Conference on Systems, Man and Cybernetics
This paper proposes a new linkage identification method based on the notion of evolution of linka... more This paper proposes a new linkage identification method based on the notion of evolution of linkages, which is designed for evolutionary computation schemes to solve combinatorial optimization problems (COP). Linkage identification is a task to identify an appropriate fragment of genes contained in a chromosome that is expected to significantly increase the fitness of the overall individuals. As a concrete target problem of the proposed scheme, we focus on the traveling salesman problem (TSP) that is known as a typical COP. The performance of the scheme is experimentally evaluated by using TSPLIB, and is compared with the performance of previous schemes. The result of experiments shows that the proposed scheme really improves the performance of the previous scheme, and the amount of improvement is 42.7% in the best case.
Proceedings of the 14th annual international symposium on Computer architecture - ISCA '87, 1987
Three-dimensional VLSI (in short, 3-D VLSI) is a new device technology that is expected to realiz... more Three-dimensional VLSI (in short, 3-D VLSI) is a new device technology that is expected to realize high performance systems. In this paper, we propose an image processing architecture based on 3-D VLSI consisting of optically-connected layers. Since the optical inter-layer connection seems to have some of useful functions due to isotropic radiation of the light, we algebraicly formulate them as the picture processing operators. Moreover, we show that the operators are available for applications such as template matching. The availability of a proposed template matching algorithm is verified by simulation.
A Self-stabilizing Marching Algorithm for a Group of Oblivious Robots
Lecture Notes in Computer Science, 2008
ABSTRACT We propose a self-stabilizing marching algorithm for a group of oblivious robots in an o... more ABSTRACT We propose a self-stabilizing marching algorithm for a group of oblivious robots in an obstacle-free workplace. To this end, we develop a distributed algorithm for a group of robots to transport a polygonal object, where each robot holds the object at a corner, and observe that each robot can simulate the algorithm, even after we replace the object by an imaginary one; we thus can use the algorithm as a marching algorithm. Each robot independently computes a velocity vector using the algorithm, moves to a new position with the velocity for a unit of time, and repeats this cycle until it reaches the goal position. The algorithm is oblivious, i.e., the computation depends only on the current robot configuration, and is constructed from a naive algorithm that generates only a selfish move, by adding two simple ingredients. For the case of two robots, we theoretically show that the algorithm is self-stabilizing, and demonstrate by simulations that the algorithm produces a motion that is fairly close to the time-optimal motion. For cases of more than two robots, we show that a natural extension of the algorithm for two robots also produces smooth and elegant motions by simulations as well.
Peer-to-Peer AOI Management Scheme with Load Balancing of Master Peers
2013 First International Symposium on Computing and Networking, 2013
In this paper, we propose a distributed scheme to realize a quick update of the AOI (Area Of Inte... more In this paper, we propose a distributed scheme to realize a quick update of the AOI (Area Of Interest) of players participating in a MMORPG. The basic idea of the proposed scheme is to dynamically adjust the number of master peers in each region using a threshold-based merge and split mechanism, where region is a part of the game field obtained by statically partitioning it. The result of simulations indicates that the proposed scheme certainly improves the update time of MOPAR proposed by Yu et al., e.g., it reduces the update time of MOPAR by 40% when all players randomly move in the game field and by 60% when a half of players gather in a specific region.
P2P overlay for CDN-P2P being aware of the upload capacity of participants
2014 20th IEEE International Conference on Parallel and Distributed Systems (ICPADS), 2014
In this paper, we propose a method to maintain a Peer-to-Peer (P2P) overlay in live streaming sys... more In this paper, we propose a method to maintain a Peer-to-Peer (P2P) overlay in live streaming systems based on a hybrid of Content Delivery Network (CDN) and P2P Technology. The key idea of the proposed method is to explicitly take into account the upload capacity of each peer in selecting peers which can directly receive the live stream from a cache server in the CDN. In addition, it prepares several backup peers to support the task of upload in such a way that a stream is fed to a P2P client if the local buffer at the client becomes scarce. The performance of the proposed scheme is evaluated by simulation.
Distributed k-mutual exclusion problem and k-coteries
Lecture Notes in Computer Science, 1991
The distributed k-mutual exclusion problem is the problem of guaranteeing that at most k processe... more The distributed k-mutual exclusion problem is the problem of guaranteeing that at most k processes are in a critical section simultaneously. This problem can be solved using the k-coterie: We first prepare a set (k-coterie) C of sets (quorums) Q of processes such that each k-set {Q1,⋯, Qk} of quorums in C contains a pair Qi and Qj (i≠j) intersecting
2011 Second International Conference on Networking and Computing, 2011
In this paper, we propose a resource management scheme for grid computers based on the notion of ... more In this paper, we propose a resource management scheme for grid computers based on the notion of market equilibrium which is commonly used in the field of game theory. In the proposed method, the price of resources is determined by the centralized manager so that: 1) the satisfaction of users is maximized, and 2) given resources are fully utilized. After describing the basic scheme for the price determination, we discuss several issues towards the implementation of the proposed scheme in actual grid environment.
Peer-to-peer (P2P) technology has gained popularity as a way to enhance system performance. Nodes... more Peer-to-peer (P2P) technology has gained popularity as a way to enhance system performance. Nodes in a P2P network work together by providing network resources to one another. In this study, we examine the use of P2P technology for video streaming and develop a distributed incentive mechanism to prevent free-riding. Our proposed solution combines WebTorrent and the Solana blockchain and can be accessed through a web browser. To incentivize uploads, some of the received video chunks are encrypted using AES. Smart contracts on the blockchain are used for third-party verification of uploads and for managing access to the video content. Experimental results on a test network showed that our system can encrypt and decrypt chunks in about 1/40th the time it takes using WebRTC, without affecting the quality of video streaming. Smart contracts were also found to quickly verify uploads in about 860 milliseconds. The paper also explores how to effectively reward virtual points for uploads.
On Linkage Identification in EC for Solving Combinatorial Optimization Problems
2005 IEEE International Conference on Systems, Man and Cybernetics
This paper proposes a new linkage identification method based on the notion of evolution of linka... more This paper proposes a new linkage identification method based on the notion of evolution of linkages, which is designed for evolutionary computation schemes to solve combinatorial optimization problems (COP). Linkage identification is a task to identify an appropriate fragment of genes contained in a chromosome that is expected to significantly increase the fitness of the overall individuals. As a concrete target problem of the proposed scheme, we focus on the traveling salesman problem (TSP) that is known as a typical COP. The performance of the scheme is experimentally evaluated by using TSPLIB, and is compared with the performance of previous schemes. The result of experiments shows that the proposed scheme really improves the performance of the previous scheme, and the amount of improvement is 42.7% in the best case.
Proceedings of the 14th annual international symposium on Computer architecture - ISCA '87, 1987
Three-dimensional VLSI (in short, 3-D VLSI) is a new device technology that is expected to realiz... more Three-dimensional VLSI (in short, 3-D VLSI) is a new device technology that is expected to realize high performance systems. In this paper, we propose an image processing architecture based on 3-D VLSI consisting of optically-connected layers. Since the optical inter-layer connection seems to have some of useful functions due to isotropic radiation of the light, we algebraicly formulate them as the picture processing operators. Moreover, we show that the operators are available for applications such as template matching. The availability of a proposed template matching algorithm is verified by simulation.
A Self-stabilizing Marching Algorithm for a Group of Oblivious Robots
Lecture Notes in Computer Science, 2008
ABSTRACT We propose a self-stabilizing marching algorithm for a group of oblivious robots in an o... more ABSTRACT We propose a self-stabilizing marching algorithm for a group of oblivious robots in an obstacle-free workplace. To this end, we develop a distributed algorithm for a group of robots to transport a polygonal object, where each robot holds the object at a corner, and observe that each robot can simulate the algorithm, even after we replace the object by an imaginary one; we thus can use the algorithm as a marching algorithm. Each robot independently computes a velocity vector using the algorithm, moves to a new position with the velocity for a unit of time, and repeats this cycle until it reaches the goal position. The algorithm is oblivious, i.e., the computation depends only on the current robot configuration, and is constructed from a naive algorithm that generates only a selfish move, by adding two simple ingredients. For the case of two robots, we theoretically show that the algorithm is self-stabilizing, and demonstrate by simulations that the algorithm produces a motion that is fairly close to the time-optimal motion. For cases of more than two robots, we show that a natural extension of the algorithm for two robots also produces smooth and elegant motions by simulations as well.
Peer-to-Peer AOI Management Scheme with Load Balancing of Master Peers
2013 First International Symposium on Computing and Networking, 2013
In this paper, we propose a distributed scheme to realize a quick update of the AOI (Area Of Inte... more In this paper, we propose a distributed scheme to realize a quick update of the AOI (Area Of Interest) of players participating in a MMORPG. The basic idea of the proposed scheme is to dynamically adjust the number of master peers in each region using a threshold-based merge and split mechanism, where region is a part of the game field obtained by statically partitioning it. The result of simulations indicates that the proposed scheme certainly improves the update time of MOPAR proposed by Yu et al., e.g., it reduces the update time of MOPAR by 40% when all players randomly move in the game field and by 60% when a half of players gather in a specific region.
P2P overlay for CDN-P2P being aware of the upload capacity of participants
2014 20th IEEE International Conference on Parallel and Distributed Systems (ICPADS), 2014
In this paper, we propose a method to maintain a Peer-to-Peer (P2P) overlay in live streaming sys... more In this paper, we propose a method to maintain a Peer-to-Peer (P2P) overlay in live streaming systems based on a hybrid of Content Delivery Network (CDN) and P2P Technology. The key idea of the proposed method is to explicitly take into account the upload capacity of each peer in selecting peers which can directly receive the live stream from a cache server in the CDN. In addition, it prepares several backup peers to support the task of upload in such a way that a stream is fed to a P2P client if the local buffer at the client becomes scarce. The performance of the proposed scheme is evaluated by simulation.
Distributed k-mutual exclusion problem and k-coteries
Lecture Notes in Computer Science, 1991
The distributed k-mutual exclusion problem is the problem of guaranteeing that at most k processe... more The distributed k-mutual exclusion problem is the problem of guaranteeing that at most k processes are in a critical section simultaneously. This problem can be solved using the k-coterie: We first prepare a set (k-coterie) C of sets (quorums) Q of processes such that each k-set {Q1,⋯, Qk} of quorums in C contains a pair Qi and Qj (i≠j) intersecting
2011 Second International Conference on Networking and Computing, 2011
In this paper, we propose a resource management scheme for grid computers based on the notion of ... more In this paper, we propose a resource management scheme for grid computers based on the notion of market equilibrium which is commonly used in the field of game theory. In the proposed method, the price of resources is determined by the centralized manager so that: 1) the satisfaction of users is maximized, and 2) given resources are fully utilized. After describing the basic scheme for the price determination, we discuss several issues towards the implementation of the proposed scheme in actual grid environment.
Uploads
Papers by Satoshi Fujita