The modern Web architecture basically follows the Representational State Transfer (REST) style. This style offers the architectural properties necessary to implement the Internet-scale Web. However, most authentication and delegation technologies that rely on session state actually deviate from the REST style. It must be noted, however, that the diversity of these technologies is imperative for the success of the Web. In this paper, we make a detailed analysis of current authentication and delegation technologies including OpenID and OAuth as well as HTML forms and cookies, and find that session state has an important role in terms of the diversity of the technologies. We also clarify that the negative impact of session state on the REST style is rather limited. On the basis of our analysis, this paper introduces the REST Using Session (RESTUS) architectural style, which is an extended REST style for sessions; this style places a session constraint on component interactions and so induces some properties required for the diversity.

This paper presents an efficient link probability control strategy for distributed estimation problems over probabilistic diffusion networks where the mean usage of communication resources is restricted. The proposed algorithm controls link probabilities so that the estimation error is minimized under given resource constraints. Simulation results show that the probabilistic diffusion least-mean squares (LMS) algorithm with the proposed probability control not only outperforms those with static probabilities but also reduces the amount of communications among nodes.

This paper presents an efficient adaptive combination strategy for diffusion algorithms over adaptive networks in order to improve the robustness against the spatial variation of SNR over the network. The diffusion least-mean square (LMS) algorithm with the proposed combination rule and its mean transient analysis are included. Simulation results show that the diffusion LMS algorithm with our combiners outperforms those with existing static combiners and the incremental LMS algorithm.

In this paper, we propose a novel method to map locations of interest by utilizing the "scent" model. Location-aware services are being actively developed as they are a key component in realizing the Ambient Intelligence (AmI) world. Our proposal provides the basics needed to create location-aware services including navigation and notification. Users' interests are loosely shared by mirroring the diffusion of a real scent, and the users can "sniff out" the locations that match their interests. Since our model is based on a simple physical phenomenon, data processing is tractable and its user interface is intuitive. Moreover, user privacy is protected by the random "wind" effect without reducing map accuracy. We conduct thorough outdoor experiments in Kanagawa Prefecture, Japan, to demonstrate our model; twelve subjects were given mobile phones with GPS devices. The results show that the "scent" model provides an intriguing map with which to locate points of interest, and that the developed applications are promising.

This paper presents an analysis of the steady-state mean-square error of an adaptive filtering algorithm using the metric projection onto a closed hyperslab, which we refer to as the hyperslab projection algorithm (HSPA). HSPA is not only a generalization of both the normalized least mean square (NLMS) algorithm and the set-membership NLMS (SM-NLMS) algorithm but also a special case of the adaptive parallel subgradient projection (PSP) method. It is known that HSPA possesses both fast convergence and robustness against noise. The approach of this paper is to employ the energy conservation relation, which enables us to avoid the transient analysis of HSPA. Under different assumptions, we obtain two results, which are generalizations of well-known results of the steady-state performance of NLMS. Extensive simulations show the good match between the theories and experiments.

This paper describes an intelligent wheelchair with a novel interface which uses visual oral motion. The wheelchair runs in various lighting environments, traditional mouth region detection method did not consider these conditions. To achieve detection of mouth region and analysis mouth motion in real-time and in various lighting environments, we proposed mouth cavity region detection method. In our system, the user moves his mouth open and close to run the wheelchair. We carried out six operational experiments and running experiments. Experiments with five subjects obtained our system is supposed to use a certain extent in a campus corridor.

This paper proposes a novel heuristic approach to the infeasible power control problem [i.e., no power allocation can provide users with specified quality of service (QoS)] in wireless communication systems. In such infeasible cases, it has been in great demand to increase the number of accepted users (i.e., users provided with the specified QoS) by certain distributed algorithms, which require no communication among base stations (BSs). The number of accepted users is often suppressed by a small number of users in severe environments, hence removing such users obviously helps many other users be accepted. The proposed algorithm, which is fully distributed, detects and removes such users based on simple criteria including: (a) the QoS is below the necessary level, and (b) the BS is already transmitting with the maximum possible power to the user. Simulation results demonstrate that the proposed algorithm significantly increases the number of accepted users with low computational complexity

An active network node architecture, called Active Packet Editing (APE), is proposed. The main concept of APE is to accelerate functions essential to active network operation, such as packet classification and NAT (Network Address Translation). The twofold architecture of APE combines a software active packet processor with a high-speed hardware packet editor. Based on preset rules (pattern, action), the packet editor classifies and modifies packets passing through the node. Upon the receipt of active packets, the software active packet processor dynamically configures the packet editor. This paper focuses on introducing the high-speed packet editing mechanism which utilizes FPGAs (Field Programmable Gate Arrays) and CAMs (Content Addressable Memories). A prototype network node based on the architecture performs Gigabit-class throughput with packet editing.

This paper discuses how to design the capacity of address cache tables for large-scale computer communication networks. We show that destination addresses of packets can, be assumed to be characterized by two types of Zipf's law. Based on the complementary use of these laws, we derive the relation between the number of accesses and the number of destination addresses. Experimental results show that the relation gives a good approximation. Applying this relation, we derive the upper/lower bounds for cache hit probability. Using the probabilities, design issues including the capacity of the cache table and aging algorithm of cache entries are also discussed.

We propose a fault simulation technique for multiple faults based on a deductive fault simulation method. The main difficulty in the development of a technique for multiple fault simulation is handling a very large number of multiple faults. Conventional deductive simulation using Linear lists to store fault sets is not appropriate for such large sets of multiple faults. Our approach to this problem is to represent sets of multiple faults by Boolean functions. We assign a distinct code word to each multiple fault and represent the fault by a minterm corresponding to its code word. Then, set operations in deductive simulation are replaced by logic operations. As an internal representation of fault sets, we use shared binary decision diagrams. The method of coding multiple faults is a key to efficient simulation. We propose a coding method called FNT coding. We also propose a fault dropping method, called prime fault dropping, which is used efficiently with our multiple fault simulation technique. Experimental results show that our technique effectively handles multiple faults at significantly lower computation cost.>

The authors propose a novel fault simulation technique for multiple faults. In order to handle a large number of multiple faults, sets of multiple faults are represented by Boolean functions, in which shared binary decision diagrams (BDDs) are used as an internal representation of Boolean functions. The authors also propose a fault dropping method, prime fault dropping, which is used efficiently to execute multiple fault simulation. The authors have succeeded in simulating 39 million double faults of a circuit of 2300 gates with about 20 Mbyte storage.>