Yasuo Tan

Activity Recognition Using Context-Aware Infrastructure Ontology in Smart Home Domain

Nowadays, activity recognition has been proposed in several researches. It is attractive to improve the ability of the activity recognition system because existing research on activity recognition systems still have an error in an ambiguous cases. In this paper, we introduce the novel technique to improve the activity recognition system in smart home domain. We propose the three contributions in this research. Firstly, we design the context-aware infrastructure ontology for modelling the users context in the smart home. The innovative data, human posture, is added into the users context for reducing the ambiguous cases. Secondly, we propose the concepts to distinguish the activities by object-based and location-based concepts. We also present the description logic (DL) rules for making the human activity decision based on our proposed concepts. Lastly, We conduct the Ontology Based Activity Recognition (OBAR) system for two purposes: to recognize the human activity, and to search the semantic information in the system, called semantic ontology search (SOS) system. The results show the system can recognize the human activity correctly and also reduce the ambiguous case.

A Multi-Purpose Wireless Network Emulator: QOMET

In this paper we present the design and usage of the multi-purpose wireless network emulator that we develop, QOMET. QOMET implements a two-stage scenario-driven approach to wireless network emulation. We give here the details of the improved model and additional functionality that make it currently possible to use QOMET to convert a real- world scenario to a sequence of network-condition descriptors for a wide range of experiments. QOMET was used on a real network testbed to perform experiments involving emulated 802.11 a/b/g WLAN technology over wired networks for several types of scenarios. We shall illustrate this in the final part of the paper, with emphasis on networked robot emulation.

QOMB: A Wireless Network Emulation Testbed

In this paper we present QOMB, a testbed we designed and implemented for the evaluation of wireless network systems, protocols and applications. The testbed uses the wireless network emulation set of tools QOMET so as to reproduce in a wired network, in real time, the wireless network conditions corresponding to a given scenario. In this context QOMET also provides support for features such as realistic virtual 3D environments, and node mobility generation. The infrastructure of QOMB is StarBED, the large-scale network experiment testbed at the National Institute of Information and Communications Technology, Hokuriku Research Center, in Ishikawa, Japan. The multi-hop wireless network emulation experimental results related to OLSR performance analysis in mesh networks and MANETs illustrate the main features and the usability of QOMB.

PID Controller for Temperature Control with Multiple Actuators in Cyber-Physical Home System

Nowadays, the need of temperature control at home is significantly demanded as the current controller used in buildings are not efficient and enough flexible to be adapted to any changes. In this research, we are focused on controlling two actuators (i.e., air-conditioner and window) using a PID controller and a hybrid controller during the summer season. We model the home temperature control (HTC) system, which is applied to monitor the desired room temperature all the times with optimal resource cost. The objective of this research is to investigate how the PID controller and the hybrid controller maintain the desired room temperature with only two actuators and minimal resource cost. In addition, we also aim to develop the practical application of cyber-physical system (CPS) for HTC system. Through MATLAB/Simulink simulation, we study and verify our proposed CPS-based HTC system.

StarBED2: Large-scale, Realistic and Real-time Testbed for Ubiquitous Networks

Nowadays many new technologies are being developed and introduced for Internet, home networks, and sensor networks. The new technologies must be evaluated in detail before deployment. However the above mentioned networks have a large number of nodes and a complicated topology. Therefore it is difficult to analyze such networks using typical network simulators. Accordingly testbeds for these networks must be able to perform accurately emulation of large-scale networks with a complex topology. In order to implement a testbed that satisfies these requirements, we developed a large-scale, realistic and real-time network testbed, StarBED, using hundreds of PCs, and switched networks. We are now implementing StarBED2, which expands StarBED so as to be suitable for emulating ubiquitous networks by introducing several new concepts. In this paper we describe first the present StarBED, its design concept, overall architecture, implemented functionalities, and some of the experiments we performed. Then we introduce StarBED2, its design policy, architecture, and additional components.

2-Hop scheme for maximum lifetime in wireless sensor networks

In wireless sensor networks (WSNs), sensors usually form a tree topology and the sensed data are transmitted to a sink using multihop communication fashion. The tree topology works effectively in handling the traffics towards the sink. However, this tree topology aggravates the waste of network resources. In particular, sensors close to the sink will overuse the energy for transmitting other sensed data and led to the residual battery drained faster. In this paper, we propose a novel 2-hop scheme to balance the energy consumed among sensors in the network by assigning each sensor a transmission probability. Simulation results reveal that our proposed 2-hop scheme outperforms the conventional scheme in term of network lifetime and data gathering delay.

A home service deployment platform with support for detection and resolution of physical resource conflicts

Services in the home environment compete for computational and physical resources. In the event of a resource conflict, the service deployment platform usually resolves it by suspending a number of services to allow the remaining services execute successfully. For the case of physical resource conflicts, we argue that a compromising solution which allows parallel execution of conflicting services successfully may exist. We propose a system that uses novel compromising algorithms and the notion of “Area of Effect” to detect and resolve such conflicts, without the need to suspend any running services. Based on the experimental results we conclude that the proposed system and algorithms are a promising solution for the problem of physical resource management.

Building Distributed Attribute-Value Trees on DHT-based Networks

Today, when a huge number of information resources appear in the Internet, one problem arising is how to search and exploit these information resources efficiently and flexibly with high scalability. We believe that the realization of multiple-attribute searching in a distributed manner is an important solution for this problem. In this paper, we propose a solution of building a distributed attribute-value tree (AV tree) on DHT-based networks to realize multiple-attribute searching. Each resource is named by an AV tree and DHT keys are created from each AV branch of a resource name. Resource information is distributed to a DHT-based network by the use of these DHT keys. Our solution keeps the locality of resource names in the key space of DHT networks such that AV branches that share a number of attribute/value pairs (AV pairs) will be mapped to a continuous portion of the key space. Therefore, multiple-attribute searching can be achieved efficiently by querying nodes responsible for a continuous portion of the key space. Our system can achieve both efficiency and a good degree of load balancing even when the distribution of AV pairs in resource names is skewed. Our simulation result shows the efficiency of our solution in respects of query success ratio and the degree of load balancing, comparing with conventional approaches.

Network-enabled Sensing Robot Emulation

We perform a demonstration of our research on sensor systems through the use of emulation on the particular case of network-enabled sensing robots. The experiment was performed remotely using virtual private network (VPN) technology on StarBED, the large-scale experiment environment of the National Institute of Information and Communications Technology (NICT), Hokuriku Research Center in Ishikawa, Japan.

Distributed emulation for the design of active tag based systems

Several choices have to be made during the design process of active tag based systems. Since the number of properties that must be decided before production and wide-scale deployment is relatively high, the use of real experiments in the design phase may be prohibitive. We propose the use of emulation for performing large-scale experiments with active tag based systems easily and in a repeatable manner. Such experiments can be used to validate the behavior of the system, and to decide the values for various system parameters. We illustrate this approach by experimental results obtained with an emulation framework that we designed and implemented for a pedestrian localization active tag based system.