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.     

Clustering based on multiple paths

This paper deals with a separation of strongly touching clusters using a concept of n-connectedness between pattern pairs, i.e., the number of paths between patterns. This new concept is similar to the concept of n-connectedness of graphs. Classification algorithms based on the number of independent paths and edge-disjoint paths are presented. It is shown that the latter has a transitivity. Finally, a simpler algorithm, i.e., a classification method based on the total number of paths, is presented. The proposed algorithm may be seen as an intermediate one between the ordinary connectedness algorithm and the maximal complete subgraph (MCS) algorithm.     

The calculation of particle deposition efficiency due to inertia,diffusion and interception in a plane stagnation flow

The particle deposition mechanism in a plane stagnation flow is investigated analytically and numerically. Particle deposition efficiency η_TID is obtained theoretically by taking into account particle inertia, diffusion and interception. It is compared with various calculated deposition efficiencies, i.e. η_T (due to inertia) + η_I (due to interception) + η_D (due to diffusion), η_TI, (due to inertia and interception) + η_D, etc. In the region where all of the three deposition mechanisms, i.e. inertia, interception and diffusion, act at the same time, real deposition efficiency η_TID is not accurately expressed by η_T + η_I + η_D. However, η_TID is nearly equal to η_TI + η_D unless the interception parameter is zero.The calculated results of particle concentration indicate that a high concentration region is formed near the deposition plate, and that the concentration becomes higher as particle inertia increases.     

Asymmetric aldol polymerization of bis(triethylsilyl enol ether) and dialdehyde

Summary Mukaiyama aldol reaction smoothly occurred between bis(triethylsilyl enol ether) and dialdehyde in the presence of Lewis acid catalyst to yield polymers that consist of -hydroxy carbonyl repeating units. When chirally modified Lewis acid catalyst was used, the optically active poly(-hydroxy ketone)s were obtained by means of the asymmetric aldol polymerization.     

Effects of low-dose cadmium exposure on biological examinations

We conducted an epidemiological study to investigate the effects of low-dose cadmium (Cd) exposure on human health in a specific area of a town in Japan where low Cd concentration was detected in rice. We compared clinical findings, urinary and whole blood Cd concentrations, and indicators of renal dysfunction between the polluted area and the control area. The study employed 44 men and 54 women from the polluted area and 21 men and 29 women from the control area. In urine analysis, as indicators of Cd exposure and possible related renal dysfunction, Cd, beta(2)-microglobulin (beta(2)-MG), alpha(1)-microglobulin (alpha(1)-MG), N-acetyl-beta-D-glucosaminidase (NAG), total protein, inorganic phosphorus, lysozyme and creatinine were quantitatively measured. In blood analysis, serum IP and creatinine and whole blood Cd were measured. No case of renal dysfunction due to Cd exposure was confirmed. However, both the urinary and whole blood Cd of the polluted area were significantly higher than those of the control area for both sexes. Urinary beta(2)-MG did not differ between the two areas. For women, urinary alpha(1)-MG was significantly higher in the polluted area than in the control area. In correlation analysis, beta(2)-MG, alpha(1)-MG and NAG, were positively correlated with both of urinary and whole blood Cd for men and women in the polluted area except for between urinary beta(2)-MG and urinary Cd for men. In the control area, the sole positive correlation observed was between urinary beta(2)-MG and whole blood Cd for men. We then examined the determinants of variations of parameters in urinary and blood tests. Potential determinants were age, sex, body mass index, an indicator of smoking habits (cigarette index) and the index of estimated Cd intake from rice (Cd-rice-index). Cd-rice-index was expressed as the product of Cd concentrations in homegrown rice multiplied by daily frequency multiplied by duration (years) of residence in the polluted area. In multiple regression analysis, whole blood Cd was independently associated with Cd-rice-index, age and gender. Variations in whole blood Cd accounted for a substantial portion of the variations in urinary Cd, although they were less influential in older individuals. Whole blood Cd was the sole independent variable related to variations in urinary beta(2)-MG. Cd-rice-index accounted for a portion of the variance in urinary NAG, while age was a more powerful determinant. It was thus revealed that the consumption of homegrown rice polluted with Cd in low concentration resulted in an elevation of whole blood Cd level and consequent increase in urinary Cd level. However, it was not clearly elucidated that the excretion of urinary low-molecular microglobulins could increase significantly in response to slight elevation of Cd body load.     

Polygon visibility ordering via Voronoi diagrams

Visibility determination is one of the oldest problems in computer graphics. The visibility, in terms of back-to-front polygon visibility ordering, is determined by updating a priority list as the viewpoint moves. A new list-priority algorithm, utilizing a property of Voronoi diagrams, is proposed in this paper. The operation is in two phases. First, in a pre-processing phase the scene is divided into Voronoi cells. A sub-list associated with each cell contains references to those polygons that intersect with it. The polygons are assigned a fixed set of view-independent priority orders within the cluster. Last, an interactive phase sorts the clusters according to the depth value of each Voronoi site. The most time-consuming work is performed during the pre-processing phase that only has to be executed once for the scene. Since all the polygons in a cell are pre-computed to obtain the fixed priority order within the cluster, a relatively simple task is left in the interactive phase, which is only to sort the clusters repeatedly when the viewpoint is changed. This method contains performance benefits that make it better shaped than previous BSP based methods.