Some WLAN (Wireless Local Area Network) roaming systems such as eduroam may experience increased authentication latency or failures, especially when authentication requests traverse multiple proxy nodes to reach their home Identity Provider (IdP). Existing systems rely on static configurations and lack adaptability to path condition changes, often leading to degraded performance.This paper presents a distributed path selection mechanism based on passive observation of EAP-TLS authentication traffic. Each proxy node locally evaluates downstream paths using metrics such as success rate and Round-Trip Time (RTT), enabling decentralized and adaptive forwarding decisions without centralized coordination.Experiments on a multi-hop simulation platform demonstrate that the proposed system improves success rates, reduces latency, and quickly recovers from failures. This work highlights the feasibility of using real authentication feedback as a lightweight yet effective basis for path optimization in federated WLAN environments.

When a site is damaged by a major disaster, there is a risk of large-scale data loss within the premises or isolation from the Internet due to network disruption. To achieve both data durability and availability from the disaster area, Risk-aware Data Protection (RDP) has been proposed to distribute redundant data to neighboring sites based on the disaster risk. However, RDP has only been studied using a method called replication, while Erasure Coding (EC) applied to RDP is still unexplored. Therefore, the challenge of this study is to quantitatively compare the effectiveness of these methods in RDP. For this purpose, we formulate evaluation indicators to measure the remaining data ratio after a disaster; and then propose how to apply several existing combinatorial optimization algorithms to RDP. Based on the results of experiments, we determined that EC performs better than replication if the probability of site damage is small.

A lot of the devices in the Internet of Things are sensors responsible for capturing environmental information and relaying it to a system or network. Oftentimes, it is important to know the location of these sensors to better contextualize the information received from them. However, the sensors are purposely simple and cheap, meaning that conventional localization techniques, such as global navigation satellite systems are not feasible. Research has been done on using unmanned aerial vehicles to estimate the location of the sensors, but issues with signal strength fluctuation and location approximation because of it are still prevalent. In this work, we propose a new method for estimating the location of sensors by exploiting the characteristics of radio wave signal propagation and creating a new flight path design, a solution to minimize the impact of variation in measurements, a novel candidate point generation through signal strength analysis, and a method to find the location based on the candidates. Through a thought-out experiment, we show that the proposed algorithm is overall significantly better than the existing solution when it comes to identifying the location of outdoor sensors.

Recognizing Customer Behavior (CB) from videos of instore cameras is important to smart retail solutions. Because of possible changes in retail needs and environments, a high degree of adaptability to different target CBs is required for Customer Behavior Recognition (CBR) methods. Existing CBR methods are mainly machine learning based models due to their remarkable recognition accuracy. However, trained models are not reusable for different target CBs. Consequently, existing CBR methods are hard to adapt to different target CBs because the necessary recollecting data and retraining models. In this paper, we propose a CBR method that recognizes CBs by combinations of primitives, each of which represents an object’s motion or objects’ relationship. Since primitives can be reused in combinations for various CBs, the proposed method is easily adaptable to changed target CBs. Experiments on two datasets indicate the good adaptability and sufficient recognition accuracy of our method.

This paper proposes a Software-Defined Network (SDN)-based Moving Target Defense (MTD) mechanism to protect the network from potential scans. The proposed mechanism can work in combination with an IPS without affecting its normal behavior. To do so, an SDN controller changes the packets' headers passing through switches using virtual IP addresses while the operation of IPS continues monitoring the devices' actual IP addresses. Preliminary results in an emulated environment show that it is possible to achieve a seamless collaboration between the MTD and IDS to detect low and high-rate scans.

SDN is an emerging network paradigm whose main characteristic is the separation of the Control from the Data Plane, allowing the implementation of innovative, robust, and flexible ways to program networks. Moreover, SDN has recently extended its coverage to Hybrid wired and/or wireless environments. However, SDN-enabled devices must be connected to a controller (i.e., a central entity) to be programmable. Therefore, if multiple controllers fail in a short period, regardless of the ample resource availability in Hybrid SDN environments, the whole network infrastructure, and the overall service are compromised. This article presents a mechanism capable of handling multi-controller failure in SDN by considering the hybrid nature of the infrastructure and the scale of the failure. Preliminary results show that by applying the proposed mechanism, it is possible to increase the device's controller coverage by up to 70% even if half of the controllers are unavailable compared to conventional approaches.

Software Defined Networking (SDN) has recently drawn attention by changing the network control paradigm. SDN devices handle the network traffic based on entries stored in their flow table. However, due to the flow table’s limited size, attacks such as DDoS can cause the table to overflow. Some of the current table overflow mitigation methods distribute flow entries to other network devices on the physical infrastructure, which might not be effective in small to medium-sized private networks. Therefore, this research proposes a method to mitigate table overflow attacks on SDN by dynamically filtering attackers using Network Function Virtualization (NFV). Preliminary results show that the proposed approach can effectively mitigate table overflow attacks without relying on network infrastructure.

Due to the diversification of devices and the spread of the Internet, many people are handling information over the network and the threat of cyber-attacks by unauthorized access and malware is also considered as a problem, and countermeasures against these threats are an urgent issue. SDN and OpenFlow are useful for network cybersecurity countermeasures because they can collect traffic statistics from switches and can interrupt communication at the switch level. In this study, we focus on detecting a port scanning as a preparation stage for cyber-attacks. In this paper, we propose port scan detection method based on the characteristics of Packet-In messages in an OF network. Also, we show its effectiveness through the experiments.

Over the past years, various anomaly detection techniques for Wireless Sensor Networks (WSNs) have been proposed in the literature. These detectors are generally only effective against particular security threats and thus many detectors have to be executed to ensure high-level security in WSNs. Due to the hardware limitations, WSNs cannot execute all of these detectors simultaneously. Thus, WSNs have to appropriately schedule when to execute a particular detector and when to execute the others. This paper presents an optimized solution by providing a unified framework that combines the usage of a costly yet highly-accurate detector, called an oracle detector, and a low cost and less-accurate detector, called a partial detector. A detection pattern is created and optimized using a first-order approximation method. Simulation results show that combining several detectors into an optimized pattern is essential to provide low execution time overhead.

When the optical network is down due to fiber cutting, optical device damage, or power failure in the large-scale disaster, it is necessary to restore the optical network early by discovering and utilizing the available network resources quickly. In this research, we propose a method to construct a temporary control and management plane network for discovering the available network resources and regaining the optical network control by integratedly using heterogeneous communication resources based on multi-agent technology. This paper shows its basic concept.

In this paper, we propose a network control method considering the disaster risk of OpenFlow control and management plane (C/M-Plane). We consider the disaster risk of both data plane (D-Plane) and the C/M-Plane. Even if the C/M-Plane is damaged and the switch becomes uncontrollable, the switch operates in the state at that time. Our method controls the entire network to keep communication according to it to maintain data transfer even if some switches become uncontrollable.

In order to get better results during brainstorming activities participants must respect some rules when they write notes about ideas and when they consider notes written by somebody else. We argue that the respect of these rules can be verified by a multi-agent system analyzing videos and notes produced by the participants in real time. This system can simplify the role of the meeting facilitator. Feedback is sent individually or is addressed globally to the entire team. This paper presents considerations about the necessity of rules, the structure of a multi-agent system for analyzing the respect of those rules and how experiments could show the level of acceptance by people of such a system. The goal of this prospective research is to add a non intrusive system during brainstorming sessions in order to enhance the quality of results.

Wireless Sensor Networks (WSNs) typically consist of failure-prone sensor nodes (SN) and more reliable sink nodes (SK). To prevent data loss due to hardware failures, the data stored in SNs' memory must be regularly transferred to SKs. Hence, choosing an appropriate data transfer rate between SN and SK is important to minimize data loss in a faulty WSN. This paper presents an analytical method to derive the optimal data transfer rate of the SN based on a Markov Model.

Researching for malware detection using machine learning is becoming active. However, conventional detection techniques do not consider the impact of attacks on machine learning, which has become complicated in recent years. In this research, we focus on data poisoning attack, which is one of the typical attacks on machine learning, and aim to clarify the influence of attacks on malware detection technology. Data poisoning attack is an attack method that intentionally manipulates the predicted result of a learned model by injecting poisoning data into training data, and by applying this, it is possible to embed a backdoor that induces mis-prediction of only specific input data. In this paper, we first propose an attack framework for backdoor embedding that prevents detection of only specific types of malware by data poisoning attack. Next, we will describe a method to generate poisoning data efficiently while avoiding attack detection by solving the optimization problem. Furthermore, we take malware detection technology using logistic regression and show the effectiveness of the our method through evaluation experiments using two datasets.

Due to the increasing need for timely and reliable access to user-generated content, Distributed Storage Systems (DSS) became more relevant in the past years. However, since they have more interconnections among layers compared to traditional network applications, load imbalance issues arise. In this paper, we propose a hybrid approach combining server and link load balancing for multipath routing in DSS. The approach is Software Defined Networking (SDN) based, and uses a process we call on-demand inverse multiplexing. Preliminary results show that, by applying the proposal, the overall throughput considerably increases and resource usage remain balanced.

Software-defined networking (SDN) not only lessens the burden of network operators but also accelerates the provision of high-quality services to various users by speeding up changes to the network configuration. Recently, Wireless Networking (WN) has gained importance as a social infrastructure to connect a large number of devices and cloud applications. Software definition technology for wireless networks is referred to as software-defined wireless networking (SDWN). We hereby propose a cognitive software-defined wireless networking (CSDWN) to enhance SDWN by applying a cognitive cycle to SDWN in addition to the development of a prototype to validate this concept.

The use of Distributed Storage Systems (DSS) has considerably increased in the past years, alongside the need for effective data transfer from storage to storage. Although current network infrastructure can reliably handle large amounts of traffic, networking techniques have not changed for several years, leading to an under-use of resources, i.e. most routing solutions still use single-path routing. In this paper, we present a pragmatic approach for multipath routing in DSS, which is based on Software Defined Networking (SDN) that uses parallel links at the edge-side. Path discovery is calculated by finding the k-maximum disjoint paths in a multigraph. Preliminary results show that, by using our multipath solution, not only the overall throughput increases but also the efficiency of resources usage.

IoT environment has spread and the use of Internet services during move has increased recently. The demand for mobility management, the technology to keep communication even when a communicating mobile node moves, is growing due to it. We proposed a SDN based mobility management scheme in our prior work to deal with inter-domain handovers, but its routing algorithm only considers the number of domains to go through and the number of flow entries to install. This prevents us from selecting suitable routes. In this paper, we show the design of a new routing mechanism that considers various parameters. This mechanism suppresses costs for changing route to carry out handover smoothly and avoids lengthy routes.

In this paper, we propose a mobility management architecture based on Software Defined Network (SDN) for multiple domain networks. In this architecture, each SDN controller cooperates with each other to optimize communication route covering multiple domain networks for seamless IP services even when the mobile devices move to other domain. This paper presents the basic design of the architecture and protocol to cover wide area for mobility management. We also show the initial experiments to confirm the behavior of our proposed architecture.

We propose a novel background subtraction method for robust region extraction of moving objects in the dynamic background. In our method, a set of recently observed frame (reference) images is used as a background model. To withstand the constant fluctuations of background appearance, a current frame (input) image is compared with every reference image, and pixels in the input image deviated from those in the reference images are extracted as moving object regions. Such a simply-structured background model enables our method to adaptively vary the size of a spatial block for comparing the input image with the reference images. Setting an appropriate size block for each subject pixel in the input image, our method increases the stability of image comparison, and then improves the robustness of region extraction. Experimental results indicate that our method outperforms the existing methods in the region extraction accuracy of moving objects in the dynamic background.

Smartphones and sensor devices have come into widespread use, and we can observe huge amounts of data from the devices via the Internet. In order to develop a network application which uses these devices effectively, we need an accurate and scalable data aggregation mechanism. In this paper, we propose a accurate data aggregation mechanism which is based on a scalable structured p2p network. The proposed mechanism is constructed by two concepts: Asynchronous Data Aggregation and Time-slot-based Data Aggregation. In the proposed mechanism, the amount of communication data required for data aggregation is O (log N), where N is the number of nodes. Additionally, the proposed mechanism achieves accurate data aggregation even if the structured p2p network is unstable. In this paper, we explain an algorithm and a communication protocol for the proposed data aggregation mechanism. Furthermore, using experimentally obtained results, we indicate advantages of our proposal over existing data aggregation mechanisms.

In this paper, we propose an advanced communication infrastructure of the agent-based middleware for ubiquitous computing environments. We focus on an adaptive communication mechanism between agent platforms, which can select a suitable communication scheme flexibly, based on properties of inter-agent communications and resource statuses. We performed some further experiments based on the results of initial experiments by using the prototype system with the proposed mechanism. From the additional results, we confirmed that the dynamic change of inter-platform communication scheme works effectively in order to realize the inter-agent communication requirements.

In ubiquitous computing environments, quality of service (QoS) in overall system may be affected when context information with excessive or deficient quality/quantity is exchanged among various entities in the environments.In this paper, we propose an adaptive control scheme of context information delivery for ubiquitous services based on QoS and quality of context information (QoC). To achieve the advanced control, we compose each entity as highly autonomous and cooperative agents. The system with this scheme can adapt to a variety of real-world environments and is able to maintain user requirements for QoS.This paper especially focuses on the design and implementation of the proposed scheme. We also illustrate the effectiveness of our scheme with some initial experiments from a viewpoint of adaptability for the changes which occur in entities in real world.

We propose a supervisory system that deals with actual situations and social aspects of users in ubiquitous computing environment in this paper. To realize a gentle and safe supervision, we have to consider social relationships between observers and the watched person to give adequate level of privacy to the services. We propose "uEyes", a ubiquitous supervisory system that introduces a new feature for the supervision, i.e., social context awareness. By using this feature, environmental information acquired from real world and knowledge on social activities of people are integrated effectively. From experimental results using a prototype of uEyes for supervising elderly people, we show that the social context awareness, as well as other components of the system, effectively works to support the supervision.

A new 3-D virtual environment (3DVE) system named "QuViE/P" has been proposed in this paper, which can greatly enhance the quality of service (QoS) that users actually feel as good as possible, when the resources for computers and networks are limited. To do this, therefore, we focus on characteristics of the user's perceptual quality evaluation on 3-D objects. In this paper, we propose an effective QoS control scheme that introduces a relationship between system's internal quality parameters and user's perceptual quality parameters. This scheme can appropriately maintain quality and functions for users and is expected to drastically improve convenience when using 3DVE under the situation that resources are limited. Experimental results obtained from using a prototype of QuViE/P show effectiveness of our scheme as follows: Even when computer resource is reduced to 30% of the required amount, our proposed scheme can preferentially keep quality of important objects. Moreover it continues to provide quality and functions that user requires. Whereas in traditional QoS control scheme, objects of importance disappeared in similar situation.

In this paper, we propose a log summarizing method to help a network manager to recognize and handle a network event. Our method can accurately extract only necessary information in real-time by stepwise information extraction technique. This feature can help the network manager to handle an event quickly with less management burden. With our experimental results, we show that our method has the ability to remove more than 60% - 90% unnecessary records, without losing any necessary information. Additionally, our method can process a log containing massive records in real-time.

We have been working on research and development of advanced network and applications called "flexible computing". We are now in the next stage of this research, strongly pressing forward the concept of flexible computing, namely, "symbiotic computing", towards next generation computing model based on co-existence of real space and digital space. In this paper, we explain basic concepts, architecture and enabling technologies of symbiotic computing that we are aiming to develop.

We have been working on construction scheme of multimedia communication system based on QoS (quality of service)-aware agent organization. In this paper, we propose a behavioral characteristics model in multiagent systems to support their design and operation. We also introduce an observation and control scheme in flexible distributed system (FDS) and configure the behavioral characteristics model to analyze the behavior of multiagent systems based on QoS of FDS. In addition, this model is applied to multimedia communication system configured by QoS-aware agent organization, and discussed the effectiveness of the proposed scheme.

Generally, the 3D-virtual space applications need powerful image processing capability of computer platform and broadband network environment. Therefore, user must perform appropriate setting of the system to receive the service from the virtual space with comfortable QoS, under the circumstances when computer and network resource are changing in almost every moment. This research is aiming for the improvement in convenience of user of 3D-virtual space system by automatic QoS control mechanism. We propose a design and implementation of 3D-virtual space with QoS awareness based on multiagent framework.

We present a design and implementation of a Flexible Videoconference System, FVCS. FVCS aims to reduce the botheration of the users under operational environments with insufficient computational resources, such as the Internet environment with the small-scale computers at home and offices, by embedding flexibility to the conventional videoconference system. We propose a design and implementation of FVCS with knowledge-based multiagent framework. We implement some kinds of prototype systems of FVCS with different types of knowledge embedded in the agent. We also perform some experiments using the prototype systems to evaluate the adaptability of the systems in response to the observed operational situations. From the results of the experiments, the adaptability is influenced by knowledge of agent, and we conclude that the knowledge-based design and implementation is reasonable for construction of FVCS.

We proposed the design and development of a multimedia communication system that utilizes multi-agent computing technology, called Flexible Video Conference System (FVCS). As a part of FVCS, the user interface (UI) presented to the system's users also requires its flexibility. In this paper we propose the adaptive display management function that is used to improve the flexibility of UI in FVCS. Using this function, the user's preference and taste about UI could be obtained easily, and meanwhile the windows of applications in FVCS could be configured properly and automatically in response to the user's preference and the status of operating environment. The design of adaptive display management function based on multi-agents is then introduced in this paper. The structure of the agent organization, the functionality of each agent, as well as the manner of organizing and collaborating of the agents are presented in detail. Also, an implementation of the proposed design is introduced.

We describe an agent-based design of multimedia processing software component in the Flexible Network Layer (FNL). In FNL, Middleware Service Unit (MSU) provides multimedia communication services for applications by combination of components for processing various multimedia data. In MSU, it is required to construct/reconstruct the necessary and sufficient functions of multimedia data processing dynamically, considering the QoS, user requirements, resource statuses, and characteristics of the media data. In this paper we propose an architecture of a Media Element Agent (MEA) to fulfill the requirement. The MEA consists of multimedia processing component and knowledge of designer developer and user of the component. We also show a scheme of multiagent-based construction of MSU with organized behavior of the agents.

We have proposed an application-oriented flow control system which decides the priority of flow according to the application utilizing situation and controls application flow. We have observed some problems at the time of experimentation using the prototype system. In this paper to improve the maintainability and availability of our proposed system by solving the problems, we propose two improving methods. We have carried out an evaluation through experiments, and the results show the effectiveness of our proposal.

We present a design and implementation of a flexible videoconference system (VCS) using multiagent computing technology. The proposed system, we named FVCS, aims to reduce the burden of the users under the operational environment with insufficient computational resources, such as the Internet environment with small-scale computers at homes and offices, by embedding flexibility to the conventional videoconference system. In this paper, we design and implement FVCS with knowledge-based multiagent framework to realize adaptability of FVCS. We also evaluate the adaptability of the prototype systems of FVCS based on an operational situation observed in its experiments. From the result of the experiments, we conclude that the multiagent-based design and implementation is reasonable for construction of FVCS.

In order to support multimedia communication over high speed networks, it is necessary to develop routing algorithms which use for routing more than one QoS parameter. This is because new services such as video on demand and remote meeting systems require better QoS. However, the problem of QoS routing is difficult and to find a feasible route with two independent path constraints is NP-complete. Therefore, QoS routing algorithms for high speed networks must be adaptive, flexible, and intelligent for efficient network management. In a previous work, we proposed a genetic algorithm (GA) based routing method. This method used only the delay time as a routing parameter. In this paper we improve the previous work in three aspects. The new QoS routing method uses two QoS parameters for routing. We implemented a new tree generating algorithm which generates and reduces the tree automatically. Furthermore, we carried out the simulations for different kinds of networks. The simulation results show that the proposed method has a better performance than a conventional GA based routing algorithm.

Asynchronous messaging systems like e-mail systems need some advanced characteristics, such as intelligence, controllability and scalability, to accomplish more effective and sophisticated message handling. We propose a framework of next generation messaging systems, Flexible Asynchronous Messaging System (FAMES), which consists of autonomous and collaborative software agents. In FAMES, various messaging functions composing of agents can be utilized to integrate heterogeneous user environment. Moreover, FAMES operates message flow in an intelligent manner, considering the receiver's own convenience and that flexible message delivery can be achieved. We designed and implemented the proposed system based on multi agent technology, and we show its effectiveness through experimental studies using a prototype system.

A concept of a flexible network is formalized as a foundation of next generation distributed systems. Considering the requisite properties of flexible networks, we propose an architecture of a flexible network called agent oriented flexible information network (AFIN) model. The model is based on the multi agent paradigm. Furthermore, we focus on a communication network which is a core component of the flexible information network. We propose an agent oriented flexible communication network (AFCN) model and demonstrate with an example the advantages of the proposed architecture of the flexible network.>