Yoshiaki Taniguchi

Kindai University · Faculty of Informatics

From Bluetooth 5.1, a direction finding function has been added that allows the receiver to measure the angle of arrival (AoA) of the wireless signal from the sender. In this letter, we propose a method for detecting pedestrians and their movement direction passing between Bluetooth devices equipped with direction finding functions. As a result of...

It would be useful to be able to detect abandoned BLE (Bluetooth Low Energy) devices or suspicious BLE devices in the surrounding area. In this letter, we propose and develop a system that supports grasping of nearby BLE devices using a smartphone. Our proposed system can support obtaining a list of MAC addresses of nearby BLE devices and identifyi...

Visualizing imperceptible wireless communications has the potential to spark interest among individuals in the field of wireless communications. In this letter, we propose a system that visualizes BLE advertising packets using an LED panel. Our proposed system consists of a Raspberry Pi and an LED panel, and the panel blinks in color depending on t...

In this letter, we propose a device identification method from observed Bluetooth Low Energy (BLE) advertising packets for tracking BLE devices even if their MAC addresses are changed periodically and randomly. In our proposed method, the combination of MAC addresses is formulated as a linear assignment problem. In addition, in a cost function of l...

In this letter, we propose a device that visualizes Wi‐Fi frames in a wireless LAN for beginners with little knowledge of networks. Our visualization device focuses on the nearest Wi‐Fi device and uses a blinking LED panel to convey the frames that are transmitted and received by that device. The blinking pattern and the color of the LED panel depe...

In this letter, we develop an acoustic spot data communication system using multiple parametric array loudspeakers, which are directional loudspeakers and can send audio in a specific direction. In our system, data are modulated and transmitted through multiple parametric array loudspeakers, and complete data reception is possible only at a specifi...

We propose a novel fish farm monitoring system utilizing visible light communication technology. In our system, a sensor node equipped with a full‐color LED module is attached to fish to transmit sensor data. A sink node equipped with an omnidirectional camera at the bottom of the cage receives sensor data. This is a simple, low‐energy approach for...

In wireless networks, data frames transmitted from wireless node are broadcasted and they can be received in a specific communication area. If an eavesdropper is located in the communication area, not only the receiver node but also the eavesdropper can receive the data. In this letter, we propose a distributed method for reducing the communication...

For practice of lure casting, information on fly distance of lure and information on rod motion are helpful. In this letter, we propose a system for supporting practice of lure casting. In our system, a sensor device with acceleration and gyroscope sensors is attached at a rod and it collects sensor data during casting motion to estimate fly distan...

We have proposed a fish farm monitoring system for achieving efficient fish farming. In our system, sensor nodes are attached at fish to monitor its health status. In this letter, we propose a method for gathering sensor data from sensor nodes to sink nodes when the transmission range of sensor node is shorter than the size of fish cage. In our pro...

We have proposed a fish-farm monitoring system. In our system, the transmission range of acoustic waves from sensors attached to the undersides of the fish is not omnidirectional because of obstruction from the bodies of the fish. In addition, energy-efficient control is highly important in our system to avoid the need to replace the batteries. In...

We have proposed a fish farm monitoring system for the efficient farming of tuna. In our system, energy efficient and adaptive control of sensor node is highly important. In addition, since a sensor node is attached to the fish, the transmission range of sensor node is not omni-directional. In this paper, we propose a data gathering mechanism for f...

As a method for supporting fish farming, this paper presents a video scene detection when farmed fry start instantaneously in a tank due to environmental stimuli. Although some environmental stimuli such as sound noises or lighting startle the fry and the stimuli bring about the instantaneous response, actual situations around the tanks in which th...

In recent years, sensor network technologies have attracted attentions in the field of the primary industry such as the aquaculture industry. We have proposed a fish farm monitoring system for developing efficient farming of tuna. In our monitoring system, a sensor node is attached at fish and its sensing data are gathered at a sink node. In the mo...

In network education, there are several benefits for conducting cooperative practice among a variety of learning levels of learners. We have proposed a hands-on IP network practice system by constructing a virtual network on a cloud server. In our past study, we introduced a pseudo cooperative practice function to our system so that cooperative pra...

In this paper, we propose a support vector regression-based method for estimating the number of people using information on the received signal strength in existing WiFi networks. To evaluate our proposed method, we construct an experimental environment in our laboratory. Through experimental evaluations, we show that our proposed method outperform...

Software-Defined Networking (SDN) has attracted attention along with the popularization of cloud environment and server virtualization. In SDN, the control plane and the data plane are decoupled so that the logical topology and routing control can be configured dynamically depending on network conditions. To obtain network conditions precisely, a n...

In tuna farming, turbidity measurement is highly important since one of the cause of death of tuna is a choking death due to muddy water. In this paper, we consider to use visible light communication modules for estimation of turbidity in underwater environments. If these modules can be used as turbidity meters, additional introduction of dedicated...

In the case of cycling at night, it is helpful for cyclist if information on bad road surface condition is obtained autonomously. In this paper, we propose a system for autonomously monitoring road surface condition by using laser light and camera modules. In our system, the laser light module emits grid laser light, and the camera module captures...

In this paper, we propose a counting method of pedestrians passing through a specific line, called counting line, in crowded scenes. In our proposed method, the number of optical flows whose segment crosses the counting line is used for estimation of the number of pedestrians. To improve accuracy of estimation, we delete optical flows detected fals...

Monitoring bad road surface condition, such as break, potholes, obstacles, is helpful to prevent accidents in the case of cycling. In this paper, we consider to use low-cost ultrasonic distance sensor for monitoring road surface condition. We design and implement a monitoring system using an off-the-shelf node with a low-cost ultrasonic distance se...

In undersea environment, development of low-cost communication module is highly important for dissemination of undersea wireless sensor networks. Some undersea wireless sensor network applications do not require high performance communication capability such as transmission distance. If the terrestrial low-cost communication module can be used in t...

Education of network security has attracted a lot of attentions due to increasing unauthorized access, lack of engineers who have network security skills, and so on. Although practice using actual computer networks is highly important for network security education, it requires costs to prepare a computer network for practice. We have proposed a ne...

In this paper, we propose a novel energy-efficient architecture for software-defined data center infrastructures. In our proposed data center architecture, we include an exhaust heat reuse system that utilizes high-temperature exhaust heat from servers in conditioning humidity and air temperature of office space near the data center. To obtain high...

As interdomain routing protocol, BGP is fairly simple, and allows plenty of policies based on ISPs' preferences. However, recent studies show that BGP routes are often non-optimal in end-to-end performance, due to technological and economic reasons. To obtain improved end-to-end performance, overlay routing, which can change traffic routing in...

In time division multiple access (TDMA) based wireless networks, graph coloring based link scheduling mechanisms are often considered to assign time slots to links. A graph coloring based link scheduling mechanism requires a radio interference estimation method to make a conflict graph from a wireless network topology, and the protocol method is us...

We proposed a workload assignment policy for reducing power consumption by air conditioners in data centers. Power consumption was estimated by computational fluid dynamics for both the conventional equipment arrangement and the tandem arrangement newly developed to reuse the exhaust heat from servers. To reduce the air conditioner power consumptio...

Under regular or heavy traffic conditions, contention-free mechanisms such as time division multiple access (TDMA) are considered as under layer mechanisms in wireless networks. In TDMA mechanisms, links are scheduled by assigning different time slots for links that interfere each other. In this paper, we propose a self-organizing link scheduling m...

We propose a method for tracking multiple pedestrians using a binary sensor network. In our proposed method, sensor nodes are composed of pairs of binary sensors and placed at specific points, referred to as gates, where pedestrians temporarily change their movement characteristics, such as doors, stairs, and elevators, to detect pedestrian arrival...

In this paper, we propose a method for estimating the number of pedestrians walking in opposite directions, as in cases of a shopping street or a sidewalk in a downtown area. The proposed method utilizes a compound-eye sensor that is constructed by placing two binary sensors for the pedestrians' movement direction and multiple binary sensors for th...

In IEEE 802.16J relay networks, time division multiple access (TDMA) is adopted for sharing wireless network resources while avoiding radio wave interference. Time slot assignment determines the degree of spatial reuse of wireless network resources and radio interference strength, which affects network performance. The relay network performance is...

We have proposed a pedestrian monitoring system to gather informar tion on pedestrians, e.g. the number of pedestrians, using ceiling-mounted compound-eye sensors in indoor environments. The compound-eye sensor consists of two passive infrared sensors which are among the most inexpensive and simplest sensors. In this paper, we make a sensing model...

In this paper, we propose two heuristic algorithms for time slot assignment in IEEE 802.16j relay networks. In the proposed methods, we calculate an appropriate group of time slots for each link in the network or calculate an appropriate group of links for each time slot. We show that the latter algorithm is better in terms of the balance between t...

We consider a pedestrian tracking system where sensor nodes are placed only at specific points so that the monitoring region is divided into multiple smaller regions referred to as microcells. In the proposed pedestrian tracking system, sensor nodes composed of pairs of binary sensors can detect pedestrian arrival and departure events. In this pap...

In this paper, we propose self-organizing trans mission and sleep scheduling mechanisms for periodically gathering sensor data at a base station in wireless sensor networks. In our proposed mechanisms, we use a conventional self-organizing communication mechanism based on phase-locking in a pulse-coupled oscillator model to propagate sensor data fr...

The Internet is composed of many distinct networks, operated by independent Internet Service Providers (ISPs). The traffic and economic relationships of ISPs are mainly decided by their routing policies. However, in today's Internet, overlay routing, which changes traffic routing at the application layer, is rapidly increasing and this challenges t...

Time slot assignment algorithms in IEEE 802.16j multi-hop relay networks often assume simple radio interference models based on the distance or the number of hops between nodes for simplicity. However, by using more detailed models that consider the signal to interference plus noise ratio, we expect to obtain more effective time slot assignment whi...

Multihoming is widely used by Internet service providers (ISPs) to obtain improved performance and reliability when connecting to the Internet. Recently, the use of overlay routing for network application traffic is rapidly increasing. As a source of both routing oscillation and cost increases, overlay routing is known to bring challenges to ISPs....

IEEE 802.16j-based wireless relay networks adopt time division multiple access, where time slots are assigned to communication links as transmission opportunities. When we employ adaptive modulation and coding for data transmission on wireless links, the transmission bitrate is affected by the signal to interference and noise ratio. Therefore, algo...

In this paper, we propose a method for estimating the number of pedestrians walking in opposite directions, as in the case of a corridor. The proposed method utilizes a ceiling-mounted compound-eye sensor composed of two binary sensors with partially overlapping sensing regions. The output of the compound-eye sensor is sent to a monitoring server,...

Multihoming is widely used by Internet service providers (ISPs) to obtain improved performance and reliability when connecting to the Internet. Recently, the use of overlay routing for network application traffic is rapidly increasing. As a source of both routing oscillation and cost increases, overlay routing is known to bring challenges to ISPs....

We propose self-organizing transmission scheduling mechanisms for periodically gathering sensor data at a base station in wireless sensor networks. In our proposed mechanisms, sensor nodes self-organize message transmission and sleep timings. To propagate sensor data from the edge of the network to the base station in order of hop counts from the b...

In this paper, the authors focus on upstream transmission in TDMA-based IEEE 802.16j and propose two time slot assignment algorithms to decrease end-to-end transmission latency. One of the proposed algorithms assigns time slots considering the hop count from a gateway node, and the other takes the path from the relay node to the gateway node into a...

In general, wireless mesh networks provides wireless Internet access service to client terminals that exist in the coverage area of the network. In such networks, the coverage area size and its overlap degree have a significant effect on network performance. In order to determine the coverage area size for each node, it is important to use the loca...

Existing systems for counting pedestrians in video sequences have the problem that counting accuracy is worse when many pedestrians are present and occlusion occurs frequently. In this paper, we introduce a method of clustering optical flows in video frames to improve the counting accuracy in cases where occlusion occurs. The proposed method counts...

The demand for automatic counting of pedestrians at event sites, buildings, or streets has been increased. Existing systems for counting pedestrians in video sequences have a problem that counting accuracy degrades when many pedestrians coexist and occlusion occurs frequently. In this paper, we introduce a method of clustering optical flows extract...

Wireless sensor network technologies have attracted a lot of attention in recent years. In this paper, we propose an energy-efficient data gathering mechanism using traveling wave and spatial interpolation for wireless sensor networks. In our proposed mechanism, sensor nodes schedule their message transmission timing in a fully-distributed manner s...

In time division multiple access (TDMA)-based wireless mesh networks, interference relationships should be considered when time slots are assigned to links. In graph theory-based time slot assignment algorithms, the protocol interference model is widely used to determine radio interference information, although it is an inaccurate model of actual r...

The Internet is composed of many distinct networks, operated by independent Internet Service Providers (ISPs). There are primarily two kinds of relationships between ISPs: transit and peering. ISPs' traffic and economic relationships are mainly decided by ISPs' routing policy. However, in today's Internet, overlay routing, which changes traffic rou...

The performance of wireless sensor networks in terms of coverage, connectivity, lifetime and robustness is greatly influenced by the initial physical placement of the sensor nodes. In this paper we propose a novel deployment method for sensor nodes, when a large number of nodes is distributed from the air in a monitoring region that is inaccessible...

In the present paper, we propose an object tracking method called scenario-type hypothesis object tracking. In the proposed method, an indoor monitoring region is divided into multiple closed micro-cells using sensor nodes that can detect objects and their moving directions. Sensor information is accumulated in a tracking server through wireless mu...

In this paper, we propose an autonomous and energy-efficient data gathering mechanism with transmission reduction for wireless sensor networks (WSNs). In our proposed mechanism, sensor nodes schedule their message transmission timing in a self-organizing manner such that they can gather sensor data over a whole WSN and transmit that data to a sink...

Radio interference should be taken into account to assign time slots to links in time division multiple access (TDMA)-based wireless mesh networks. In many graph theory-based time slot assignment algorithms, the protocol interference model is widely used to obtain radio interference information, although this model is considered to be inaccurate wh...

In IEEE 802.16j wireless multihop networks, transmission latency from relay nodes to a gateway node is one of the important performance metrics. The transmission latency is mainly affected by a scheduling delay at every relay node, which is determined by algorithms for assigning time slots to wireless links between relay nodes. In this paper, we pr...

In this paper, we propose an assignment algorithm of time slots for wireless links in IEEE 802.16 multi-hop relay networks. The main purpose is to reduce transmission latency between user stations and base stations as well as maintaining total network throughput. The proposed algorithm is based on the existing method, which aims better network thro...

In recent years, wireless communication technologies such as ZigBee have been developed. By constructing a wireless sensor network from infrared sensors with those wireless technologies, it is possible to track moving objects in a wide monitoring region. In this paper, we propose an object tracking method by dividing a wide monitoring region into s...

In wireless mesh networks based on IEEE 802.16 WiMax, each mesh node has its own service area that provides wireless Internet access service to client terminals. The network performance degrades due to radio interference when multiple service areas overlap with each other. To avoid this problem, information of the exact location and size of the ser...

In wireless sensor networks (WSNs), the frequency of sensing and data gathering depends on application requirements and surrounding conditions. In this paper, we propose a data gathering scheme adaptive to sensing requirements for WSNs composed of sensor nodes with multiple sensing capabilities. To accomplish self-organizing control, we adopt the r...

By applying a proxy mechanism widely used in WWW systems to video streaming systems, low-delay and high-quality video distribution can be accomplished without imposing extra load on the system. The video streaming system proposed in this paper consists of a video server and multiple proxy servers. In our mechanism, proxies communicate with each oth...

With the increase in computing power and the proliferation of the Internet, video streaming services have become widely deployed. In this paper, we propose, design, implement, and evaluate a proxy caching system for MPEG-4 video streaming services. With our system, high-quality, low-delay, and scalable video distribution can be accomplished. Throug...

We have proposed a simple and energy-efficient communication mechanism which can organize a variety of communication depending on dynamically changing application requirements. In this demonstration, we show that our mechanism can gather or diffuse information in accordance with application requirements in a dynamic wireless sensor network.

We have proposed a self-organizing communication mechanism for wireless sensor networks where a large number of sensor nodes are deployed. In this paper, we briefly introduce and overview our communication mechanism. In our mechanism, to accomplish application-oriented periodic communication without any centralized controls, we adopt traveling wave...

In this paper, we propose and evaluate a selforganizing communication mechanism for wireless sensor networks where a large number of sensor nodes are deployed. To accomplish application-oriented periodic communication without any centralized controls, we adopt traveling wave phenomena of a pulse-coupled oscillator model by regarding sensor nodes as...

In this paper, we propose and evaluate a self-organizing communication mechanism for wireless sensor networks where a large number of sensor nodes are deployed. To accomplish application-oriented periodic communication without any centralized controls, we adopt traveling wave phenomena of a pulse-coupled oscillator model by regarding sensor nodes a...

In this paper, we propose a self-organizing communication mechanism for a wireless sensor network where a large number of sensor nodes are deployed. To accomplish application-oriented periodic communication without any centralized controls, we adopt traveling wave phenomena of a pulse-coupled oscillator model by regarding sensor nodes as oscillator...

In this paper, we propose, design, implement, and evaluate a proxy caching system for MPEG- 4 video streaming services for heterogeneous users. In our system, a video stream is divided into blocks for efficient use of the cache buffer and the bandwidth. A proxy retrieves a block from a server, deposits it in its local cache buffer, and provides a r...

The development of low-cost microsensor equipment having the capability of wireless communications has caused sensor network technology to attract the attention of many researchers and developers. In this paper, we propose a fully-distributed and self-organizing data gathering scheme for a network where a large number of sensor nodes are deployed....

The proxy mechanism widely used in WWW systems offers low-delay and scalable delivery of data by means of a "proxy server". By applying proxy mechanism to video streaming systems, high-quality and low-delay video distribution can be accomplished without imposing extra load on the system. We have proposed proxy caching mechanisms to accomplish the h...

SUMMARY The proxy mechanism widely used in WWW systems offers low-delay data delivery by means of "proxy server". By applying proxy mechanisms to video streaming system, we expect that high-quality and low-delay video distribution can be accomplished without introducing extra load on the system. In addition, it is effective to adapt the quality of...

The proxy mechanism widely used in WWW systems o#ers low-delay data delivery by means of "proxy server". By applying the proxy mechanisms to the video streaming system, we expect that high-quality and low-delay video distribution can be accomplished without introducing extra load on the system. In addition, it is e#ective to adapt the quality of ca...