A human being can communicate while working at the same time. However, teleoperated humanoid robots that can work and communicate simultaneously are currently too complex and expensive. We propose an “Augmented Avatar” that can perform both work and communication simultaneously at a low cost. The authors have developed two types of Avatars: a Manipulation Avatar with minimal functions tailored for work, and a Communication Avatar that mimics the human body structure to facilitate communication. The aim of this project is to develop an AVATAR system that enables operators to seamlessly operate the two avatars without using a wearable control interface. In this paper, we report on the construction and operation test results of this prototype. The prototype system has been well received in an international AVATAR competition in which 820 teams participated, placing 12th. This paper also discusses operability based on the experience gained at this competition.

Bluetooth Low Energy (BLE)-based localization is a promising candidate of indoor localization for low power mobile and Internet of Things (IoT) systems. Localization accuracy of BLE-based localization systems is lower than other localization technologies relying on wideband wireless communication such as WiFi due to limited channel bandwidth. In our previous paper, we proposed an accuracy improvement method named separate channel fingerprinting (SCF), which, however, suffers from a high maximum localization error more than 6 meters. This paper therefore presents 2-step separate channel fingerprinting (2SSCF). 2S-SCF first coarsely estimates location by conventional BLE fingerprinting and utilizes SCF to estimate the fine-grained location. We experimentally demonstrate that 2S-SCF successfully reduced localization errors 95 % of time with a small maximum localization error.

Sensor localization is one of the big problems when building large scale indoor sensor networks since GPS is unavailable in indoor environments. Many indoor localization systems have been proposed to tackle the sensor localization problem, yet user cooperation or many anchor nodes are required. In this paper, we propose a sensor localization system using WiFi APs as anchors. WiFi APs are largely installed in indoor environments and are managed by a network system manager. Using WiFi APs as anchors, we can localize sensor nodes without newly deployed anchor nodes. As a first step of our sensor localization system, this paper presents a WiFi AP-RSS monitoring system using sensor nodes. Sensor nodes are equipped with IEEE802.15.4 (ZigBee) modules, which cannot demodulate WiFi (IEEE802.11) signals. We therefore developed a cross-technology signal extraction scheme on sensor nodes. We herein describe the design and implementation of our AP-RSS monitoring system. The experimental evaluations show that our AP-RSS monitoring system successfully retrieves AP-RSS with an average error of 1.26dB.

A critical problem with location fingerprinting is the considerable time and effort spent measuring received signal strengths at all location candidates to create the survey database. To reduce this cost, existing methods use a signal path loss model to interpolate part of the survey database from data actually measured at location candidates. However, the positioning accuracy can become degraded, especially in an indoor area delimited by walls. In this paper, we confirm the degradation in accuracy of the existing method through a preliminary experiment, and propose an accurate interpolation method for survey databases. In the proposed method, part of the survey data is interpolated using a path loss model containing wall attenuation. Furthermore, to confirm the effectiveness of the proposed method, we evaluate the location estimation performance with the interpolated survey database and also verify the interpolated data. The proposed method improves the positioning accuracy by 25% over that of the existing method.

We have developed an adhoc wireless positioning network (AWPN) scheme for information-oriented construction that can temporarily and easily provide a positioning area in both indoor and outdoor environments. The particular requirements of AWPNs are easy deployment and easy configuration because the network should be removed on completion of construction and must frequently accompany the active construction section as it shifts from area to area. In this paper, we propose a localization scheme based on the multilateration method to fulfill the requirements of such AWPNs. The proposed scheme locally and dynamically calibrates the attenuation coefficient defined in the path loss model for radio wave propagation in order to reflect local, fresh propagation characteristics. The results of evaluations conducted on the efficacy of our proposed scheme indicate that it reduces the average error by 30% relative to the conventional approach.

This paper proposes a mechanism to share and utilize various sensors among multiple Android terminals for a functional enhancement and a battery life extension. The most important contribution is how to emulate the value from remote sensor as a value from a local sensor. By this emulation, all the other applications existed on Google Play Market can utilize remote sensors without any modification.

Multipoint relaying is a key concept adopted in the optimized link state routing protocol (OLSR). It realizes efficient flooding of topology control (TC) messages. It simultaneously supports generating small topology information which is enough to find the shortest path for any pair of nodes. In this paper, we propose a method to find more efficient multipoint relay (MPR) set, in terms of reducing topology control traffic of OLSR. Our method shares MPRs between a node and its neighbor nodes, to reduce the MPR ratio. The MPR ratio is defined as the number of MPR nodes divided by the total number of nodes in the network. By decreasing the MPR ratio, the number of TC message generation is decreased. To overlap the MPR set with MPR sets of the neighbors, each node computes the degree of coverage for each of its MPRs, and appends the degrees into HELLO messages. When a node computes its MPR set, the node intends to share MPRs by referring neighbors' MPR sets and the degrees of their MPRs. Our MPR selection algorithm keeps the size of MPR set no more than that of the conventional MPR selection. Through simulations, the MPR ratio and the number of OLSR packets reduce by 6% and 4%, respectively, in moderately dense networks.

In the region of Japan, broadband network and informatization have spread. However the field of agriculture has not come willingly. The infrastructure that has not been enough in mountainous areas, but various initiatives of computerization are being started using production and distribution as the subjects. Since this began in reality, there are still insufficient matters that have been resolved in regards to the technical validations and cost effectiveness. Therefore necessitates pouring in a tremendous amount of expertise, possibility is ICT and its related technologies of sensors. In our research and developments, we create demo hardware for the experiment using in the farm collected data. On the other hand, making study group with farmers for accumulation of data and experience. That visualized information configure to the platform of knowledge management.

In this paper, we propose a dynamic channel assignment method that utilizes location information of mobile terminals to calculate the optimal channel scheme in indoor WLAN positioning systems. Our method could achieve two goals: (a) the optimal channel scheme can guarantee a maximum throughput of overall wireless network. (b) terminals can communicate and be located simultaneously in our system. By taking advantage of positioning system, we can know the location of terminals, and such location information can be used to optimize network capacity through assigning appropriate channels. Assigning different channel to neighbouring APs is not only for optimizing network capacity, but also for improving the positioning accuracy due to that it can immigrate the interference among APs and receive accurate signal strength. To confirm its effectiveness, we evaluate our approach by simulation. We compare our method with the single, random, and static methods and the LCCS method. The results illustrate that the throughput of our channel assignment method is higher than other methods.

In this paper, we propose name resolution middleware that involves positional awareness to identify target hosts in wireless visible area communication (WVAC). WVAC is a wireless communication network that enables users to exchange information with nearby hosts, especially within the users' visible area, wherein the underlying network can be locally and temporarily constructed without the aid of any centralized administration. In such communication, the proposed middleware assists the user to intuitively identify a target host by presenting the relative positional relationship among the neighbor hosts. The middleware possesses the following characteristics: (1) it provides simple APIs to be easily utilized by various applications, (2) a dedicated server preliminarily located in the network is not required to operate it, and (3) it adopts a positioning method that could estimate the relative locations of neighbor hosts without any pre-configuration. Finally, we construct a prototype system and evaluate the middleware using this system. The results indicate that this middleware can sufficiently work even on resource-limited mobile devices.

In this paper, we propose three heuristics for high-efficiency selections of MPRs (multipoint relays) in link state QoS routing protocol: MIMS (maximizing integration metric selection), MQES (maximizing QoS-efficiency selection), and MCIS (minimizing cost-inefficiency selection). The basic approach of these selections is to determine a smaller set of MPRs that provide better QoS paths between any two nodes. The main objective in doing so is to maximize the QoS (quality of service) effect while limiting routing overhead for flooding control traffic. In addition, we evaluate the performance of the routing protocols with the proposed selections by simulation. The results indicate that the proposed methods achieve high-efficiency selection; as compared to an existing MPR selection taking into account the QoS requirements, MIMS reduces the maintenance cost by 30%, while the throughput of the resultant path is decreased by 13%, and MCIS reduces the cost by 21% without any decrease in the throughput.

IEEE802.11e standard adopts several important techniques to guarantee the quality of service (QoS) of multimedia communications in wireless LAN. A key technique introduced in the standard is an efficient media access control based on hybrid coordination function (HCF), in which each flow is assigned an appropriate transmission opportunity (TXOP) to satisfy several requirements on the flow such as the delay bound and the communication bandwidth. Although it could provide an efficient tool to guarantee the QoS in wireless LAN, HCF has a serious drawback such that a useless bandwidth assignment frequently occurs, which is primarily due to the limitation of the scheme such that all flows share the same service interval (SI). In this paper, we propose a new scheduling scheme that associates each flow with its own SI according to the hardness of the delay bound. The effect of the scheme is experimentally evaluated by simulation. The result of simulations indicates that the number of admitted flows and the data transmission rate certainly increase by the proposed scheme

In wireless LAN, several terminals could share a single communication channel by using an appropriate media access control (MAC) mechanism. However, existing MAC schemes for wireless LAN have serious drawbacks such that it significantly degrades the throughput if it frequently occurs a collision of frames or a useless assignment of communication bandwidth. In this paper, we propose a new MAC scheme for wireless LAN to realize an efficient utilization of the communication bandwidth while suppressing the probability of frame collisions. The basic idea of the scheme is to conduct a channel assignment for each group which is dynamically constructed based on the unique identifier that is assigned to each terminal beforehand. The scheme could be customized by appropriately tuning parameters according to the given communication environment. The effect of the scheme is estimated by simulation. By the result of simulations, it is confirmed that the proposed scheme could achieve a stable performance for any access frequency.

In this paper, we propose a new class of parallel branch-and-bound (B&B) schemes. The main idea of the scheme is to focus on the functional parallelism instead of conventional data parallelism, and to support such a heterogeneous and irregular parallelism by using a collection of autonomous agents distributed over the network. After examining several design issues toward the implementation of a prototype of the distributed B&B system, we illustrate the result of our preliminary experiments conducted to estimate the performance of the proposed scheme. The result shows that it could cause a significant performance improvement if each agent autonomously changes its function type according to the change of the underlying environment.

This paper proposes a fast branch-and-bound algorithm for solving the multiprocessor scheduling problem. The key point of our method is the proposal of an efficient quadratic algorithm for calculating the Fernandez and Bussell's (1973) lower bound. In the following, we discuss about the trade-off between the cost for calculating a lower bound and the size of pruned subtrees. Several experiments are conducted to evaluate the goodness of the proposed method.

We propose a new scheduling method that can simultaneously achieve two main goals of task scheduling in distributed parallel systems; i.e., to minimize the execution time of a parallel job without disturbing the execution of other jobs. We challenge to achieve those goals by introducing a new scheduler, called active scheduler, that controls the priority of parallel programs dynamically and balances the workload of computers, depending on the current status of the runtime environment. The priority of parallel programs is controlled by controlling the concurrency of the programs. We implemented a prototype system to evaluate the effectiveness of active scheduler. The results of experiments imply that the overhead of introducing the active scheduler is bounded by 15% of the original execution time, and it is in fact effective to adjust the execution of parallel programs to an actual distributed parallel processing environment in which many users execute their jobs at the same time.

We designed and built an information announcement basic software system that realizes a new using style, called the TAM. This style regards a mobile computer as a server as well as a client. In order to effectively announce information from a mobile computer as a server the system uses stationary computers, called SMHs, that manages mobile computers. The effectiveness of the system has been shown. The system works well and gives a useful environment to clients. In the system, however, communications between a client and a server are always done via the SMH computer associated with the server. This communication path is redundant in some cases. The server cannot provide high quality services to the client because of the redundancy. We design a new information announcement system, called the WOR, which is expansion of the TAM to solve the problem of the redundant path. In the WOR, we assume that a SMH is located at every network domain. The communication method uses two types of the SMH; Home SMH (HSMH) and Foreign SMH (FSMH). The HSMH is the same as the SMH in the TAM. The FSMH finds a shorter path for the mobile computer to provide the service to a client. We show the system to be a useful mobile computing environment to clients by implementing the system.

The bandwidth problem between a mobile computer and an access point is pointed out, and a copy update mechanism, which can make the best use of the limited bandwidth, is proposed. If the bandwidth of a network is not sufficient, a mobile computer cannot announce all resources, and cannot update some copies on fixed computers. To satisfy client's requests with given bandwidth as much as possible, the proposed mechanism limits traffic of storage type resources in order to announce non-storage type resources prior to storage type resources. Traffic is controlled by limiting the number of concurrent update operations for announcing storage type resources. We implement the prototype and evaluate it. The results show that it can stably announce non-storage type resources.

An individual speaker is thought to have his own subspace in which his phonetic information is included. However, conventional speaker-independent HMMs ignore the speaker subspaces and gather speech data spread widely in the observation space. Then they cause probability distribution flatness of HMMs and the resultant recognition errors. To solve this problem, we propose a method (1) to separate the speaker characteristics by constructing the individual speaker subspace, (2) to recognize speakers based on the subspaces and (3) to produce speaker normalized speech data by projecting speech data into his subspace and to recognize them.