Mean–variance relationship of the number of flows in traffic aggregation and its application to traffic management

We consider the mean–variance relationship of the number of flows in traffic aggregation, where flows are divided into several groups randomly, based on a predefined flow aggregation index, such as source IP address. We first derive a quadratic relationship between the mean and the variance of the number of flows belonging to a randomly chosen traffic aggregation group. Note here that the result is applicable to sampled flows obtained through packet sampling. We then show that our analytically derived mean–variance relationship fits well those in actual packet trace data sets. Next, we present two applications of the mean–variance relationship to traffic management. One is an application to detecting network anomalies through monitoring a time series of traffic. Using the mean–variance relationship, we determine the traffic aggregation level in traffic monitoring so that it meets two predefined requirements on false positive and false negative ratios simultaneously. The other is an application to load balancing among network equipments that require per-flow management. We utilize the mean–variance relationship for estimating the processing capability required in each network equipment.     

User Modeling in Spoken Dialogue Systems to Generate Flexible Guidance

We address the issue of appropriate user modeling to generate cooperative responses to users in spoken dialogue systems. Unlike previous studies that have focused on a user’s knowledge, we propose more generalized modeling. We specifically set up three dimensions for user models: the skill level in use of the system, the knowledge level about the target domain, and the degree of urgency. Moreover, the models are automatically derived by decision tree learning using actual dialogue data collected by the system. We obtained reasonable accuracy in classification for all dimensions. Dialogue strategies based on user modeling were implemented on the Kyoto City Bus Information System that was developed at our laboratory. Experimental evaluations revealed that the cooperative responses adapted to each subject type served as good guides for novices without increasing the duration dialogue lasted for skilled users.     

Ion exchange of intercalation compounds from WOP2O7 and intercalation ofn-alkylamines

Ion exchange of Na _x WOP₂O₇ ·nH₂O (x 1.4) prepared from WOP₂O₇ was attempted, using alkaline and alkaline earth ions. The degree of exchange was observed to be >50% at 90° C except for Mg²⁺. The basal spacing of ion-exchanged materials for the hydrated phase were dependent on the number of water molecules in the interlayer spaces, while those for the dehydrated phase increased with the size of ions in the interlayer spaces. The network of water molecules linked by the hydrogen bond in the interlayer spaces seems to determine the basal spacing. By the ion-exchange reaction,n-alkylammonium ions were intercalated into the interlayer spaces of Na _x WOP₂O₇ ·nH₂O (x 1.4) and Sn _x H _y WOP₂O₇ ·nH₂O (2x +y 0.5). In spite of the difference in the charge density of the host layer, a similar arrangement of alkyl chains in the interlayer spaces resulted, and neutral amines were considered to be intercalated as well as ammonium ions. Direct reaction ofn-alkylamine with WOP₂O₇ produced an intercalation compound without reduction of tungsten. The arrangement of the amines in the interlayer spaces is similar to that supposed to the ion-exchanged derivatives when heated at 140° Cin vacuo.     

Control of three-link underactuated manipulators using a switching method of fuzzy energy regions

In general, manipulators used for industry and in academic laboratories have actuators to drive each joint. On the other hand, underactuated manipulators handled by our research have some passive or free joints without actuators and brakes. We recently developed a switching method of fuzzy energy regions to control such manipulators. In such a method, it is necessary to design parameters related to energy regions and the gains of some partly stable controllers based on the computed torque method. Here, the switching method is applied for a three-link underactuated manipulator. We optimize such design parameters related to fuzzy energy regions by a genetic algorithm. The effectiveness of the present method is illustrated with some simulations. This work was presented in part at the 12th International Symposium on Artificial Life and Robotics, Oita, Japan, January 25–27, 2007     

Multi agent architecture for dynamic incremental process planning in the flexible manufacturing system

Due to rapid changes of markets and pressures of competitions, industries are adopting their production ways to support diversity of customer’s needs and increase of new product developments. This paper deals with development of an agent-based architecture of dynamic systems for process planning in the manufacturing systems. In consideration of alternative manufacturing processes and machine tools, the process plans and the schedules of the manufacturing resources are generated incrementally and dynamically. A previously proposed negotiation protocol is customized and improved to generate suitable process plans for the target products real-timely and dynamically, based on the alternative manufacturing processes. The alternative manufacturing processes are presented by the process plan networks and the suitable process plans are searched and generated to cope with both the dynamic status and disturbances of the manufacturing systems. We initiatively combine the heuristic search algorithms of the process plan networks with the negotiation protocols, in order to generate suitable process plans.     

Submodular fractional programming for balanced clustering

We address the balanced clustering problem where cluster sizes are regularized with submodular functions. The objective function for balanced clustering is a submodular fractional function, i.e., the ratio of two submodular functions, and thus includes the well-known ratio cuts as special cases. In this paper, we present a novel algorithm for minimizing this objective function (submodular fractional programming) using recent submodular optimization techniques. The main idea is to utilize an algorithm to minimize the difference of two submodular functions, combined with the discrete Newton method. Thus, it can be applied to the objective function involving any submodular functions in both the numerator and the denominator, which enables us to design flexible clustering setups. We also give theoretical analysis on the algorithm, and evaluate the performance through comparative experiments with conventional algorithms by artificial and real datasets.     

Effects of alkaloids from Aconitum yesoense var. macroyesoense on cutaneous blood flow in mice

Nine alkaloid constituents in the root of Aconitum yesoense var. macroyesoense, as well as three acetylated derivatives, were examined for their peripheral vaso-activities by measuring laser-flowmetrically the cutaneous blood flow in the hind foot of mice after intravenous administration. The major constitutive delcosine (1), 14-acetyldelcosine (2) and lucidusculine (3), respectively, had little or very mild vaso-activity. Kobusine (4) and pseudokobusine (5) and three minor constituents, luciculine (6), 1-acetylluciculine (7) and dehydroluciculine (8), together exhibited a rapid increase in blood flow reaching a peak with a magnitude almost equal to that produced by hydralazine, when administered intravenously at the same dosage level of 20 mg/kg. Among them, 4 was characterized by successive reversal of the increase to a decrease in blood flow, while 7 produced a flow with a more delayed peak time. Dehydrolucidusculine (9) exhibited a transient decrease in blood flow prior to occurrence of the increase, as did papaverine. Consequently, it is assumed that the alkaloids, especially those of the C20-diterpenoid type, in the root of this Aconitum plant have peripherally vaso-dilating activities to varying degrees in mice, probably due to their direct action on the cutaneous microvasculature in a similar fashion to that shown by hydralazine. The laser blood flowmetric method would be useful as an in vivo means of qualitative as well as quantitative screening of chemically modified derivatives of peripherally vasoactive agents in mice.     

Crystal structures of CdTi2O4(OH)2 and LaTiSbO6

The crystal structures of two PbSb₂O₆-type compounds containing titanium, CdTi₂O₄(OH)₂ and LaTiSbO₆ were refined by X-ray powder diffraction data. For both compounds structure refinements with the space group were successful and the R-factors were R_WP = 6.46% and R_P = 4.90% for CdTi₂O₄(OH)₂ and R_WP = 9.55% and R_P = 7.17% for LaTiSbO₆. These crystal structures were the same as that of the typical PbSb₂O₆-type compound in spite of the existence of protons in the interlayer or two different metal ions in the layer.     

On-Site Fabrication of Crystalline Cerium Oxide Films and Patterns by Ink-Jet Deposition Method at Moderate Temperatures

Crystalline CeO₂ films and patterns have been successfully fabricated in a single-step process at moderate temperature. In this process, the combination of the ink-jet technique and depositing the precursor on a hot substrate (≤300°C) gave crystalline CeO₂ without further heat treatment. X-ray diffraction analysis revealed that the phase formed was crystallized ceria with nanosized (<10 nm) crystallites. The film thickness was several hundred nanometers and the pattern width was about 150 μm. Scanning electron microscopy analysis showed that the films and patterns were free of cracks and adhered to the substrate. This is the first report about the direct patterning of crystalline CeO₂ without postfiring or posttreatments like masking, etching, etc.     

End-to-end security in the presence of intelligent data adapting proxies: the case of authenticating transcoded streaming media

We consider the problem of maintaining end-to-end security in the presence of intelligent proxies that may adaptively modify data being transmitted across a network. The video coding community considers this problem in the context of transcoding media streams, but their approaches either fail to address authentication or fail to provide meaningful security guarantees. We present two provably-secure schemes, LISSA and TRESSA, that allow an intelligent network intermediary to intercept a stream signed by a content provider, and adapt it dynamically, while preserving the ultimate receiver's ability to securely verify the content provider's signature (and, hence, authenticity and integrity of the data received). Our schemes allow the intermediary to selectively remove portions of the stream and, thus, permit common media transcoding techniques such as scalable compression and multiple file switching. Moreover, a content provider only has to encode and sign its entire data stream once, as opposed to nondynamically encoding and signing different versions for each anticipated combination of device, network configuration, and channel condition. Our implementation results demonstrate efficiency.