Automatic 3D model reconstruction of cutting tools from a single camera

Collision detection by machining simulation requires the 3D models of rotating cutters. However, the 3D models of a cutter and holder are not always available. In this paper, a new method is proposed to design an automatic vision-based 3D modeling system, which is able to quickly reconstruct the 3D model of a cutter and holder when they are installed onto the spindle. Only a single camera is mounted on the machine tool to capture the image of the rotating cutter and holder. By viewing the rotating cutter and holder as an object of surface of revolution, the contour of the imaged cutter and holder can be used to reconstruct the 3D model as a stack of circular cross-sections. Then the complete generating function of the cutter and holder can be recovered from the cross-sections. Finally, the 3D model of the cutter is built by rotating the generating function around the spindle axis. The effectiveness and accuracy of the proposed method are verified by experiments on-machine using 12 kinds of cutters and holders, which can satisfy the requirement of collision detection.     

eSeeTrack--visualizing sequential fixation patterns

We introduce eSeeTrack, an eye-tracking visualization prototype that facilitates exploration and comparison of sequential gaze orderings in a static or a dynamic scene. It extends current eye-tracking data visualizations by extracting patterns of sequential gaze orderings, displaying these patterns in a way that does not depend on the number of fixations on a scene, and enabling users to compare patterns from two or more sets of eye-gaze data. Extracting such patterns was very difficult with previous visualization techniques. eSeeTrack combines a timeline and a tree-structured visual representation to embody three aspects of eye-tracking data that users are interested in: duration, frequency and orderings of fixations. We demonstrate the usefulness of eSeeTrack via two case studies on surgical simulation and retail store chain data. We found that eSeeTrack allows ordering of fixations to be rapidly queried, explored and compared. Furthermore, our tool provides an effective and efficient mechanism to determine pattern outliers. This approach can be effective for behavior analysis in a variety of domains that are described at the end of this paper.     

Low cost inductor current sensing for power converters using feedback compensation

One of the key components in the current mode control of power converters is the sensing of inductor current. Traditional low cost implementation is to add a sensing resistor in series with the inductor to sense the inductor current. This will reduce the overall efficiency of the power converter. An alternative is to apply a current transformer to the inductor to sense its current. This however will significantly increase the cost of power converters. One low cost implementation is to add a resistor–capacitor network in parallel with the inductor so that the inductor current can be derived from the capacitor voltage. The problem of this implementation is that the capacitor voltage is very sensitive to temperature variations. In this paper, a simple feedback loop is applied to the sensed capacitor voltage based on the steady state duty ratio of power converters such that the sensed inductor current will be independent of temperature variations. The sensing element with feedback compensation can be applied to inductors fitted to power converters such as buck converters and boost converters. Although experimental studies based on a buck converter were carried out to illustrate the correctness of the new sensing technique, the proposed technique is applicable to other converter topologies.     

Plans, Actions and Dialogues Using Linear Logic

We describe how Intuitionistic Linear Logic can be used to provide a unified logical account for agents to find and execute plans. This account supports the modelling of agent interaction, including dialogue; allows agents to be robust to unexpected events and failures; and supports significant reuse of agent specifications. The framework has been implemented and several case studies have been considered. Further applications include human–computer interfaces as well as agent interaction in the semantic web.     

Service bid comparisons by fuzzy ranking in open railway market timetabling

In an open railway access market, the Infrastructure Provider (IP), upon the receipts of service bids from the Train Service Providers (TSPs), assigns track access rights according to its own business objectives and the merits of the bids; and produces the train service timetable through negotiations. In practice, IP chooses to negotiate with the TSPs one by one in such a sequence that IP optimizes its objectives. The TSP bids are usually very complicated, containing a large number of parameters in different natures. It is a difficult task even for an expert to give a priority sequence for negotiations from the contents of the bids. This study proposes the application of fuzzy ranking method to compare and prioritize the TSP bids in order to produce a negotiation sequence. The results of this study allow investigations on the behaviors of the stakeholders in bid preparation and negotiation, as well as evaluation of service quality in the open railway market.     

Latent growth curve modeling for longitudinal ordinal responses with applications

In this paper, we consider the use of the latent growth curve model to analyze longitudinal ordinal categorical data that involve measurements at different time points. By operating on the assumption that the ordinal response variables at different time points are related to normally distributed underlying continuous variables, and by further modeling these underlying continuous variables for different time points with the latent growth curve model, we achieve a comprehensive and flexible model with straightforward interpretations and a variety of applications. We discuss the applications of the model in treatment comparisons and in the analysis of the covariate effects. Moreover, one prominent advantage of the model lies in its ability to address possible differences in the initial conditions for the subjects who take part in different treatments. Making use of this property, we also develop a new method to test the equivalence of two treatments that involve ordinal responses obtained at two different time points. A real data set is used to illustrate the applicability and practicality of the proposed approach.     

Equilibrium analysis through separation of user and network behavior

Internet complexity makes reasoning about traffic equilibrium difficult, partly because users react to congestion. This difficulty calls for an analytic technique that is simple, yet have enough details to capture user behavior and flexibly address a broad range of issues.This paper presents such a technique. It treats traffic equilibrium as a balance between an inflow controlled by users, and an outflow controlled by the network (link capacity, congestion avoidance, etc.). This decomposition is demonstrated with a surfing session model, and validated with a traffic trace and NS2 simulations.The technique’s accessibility and breadth are illustrated through an analysis of several issues concerning the location, stability, robustness and dynamics of traffic equilibrium.     

The clinical assessment of cancer tests: a statistical approach to the prediction of "false positive" rates from controls

As the sensitivity of the new in vitro cancer detection techniques increases, a larger number of "false positive" results can be expected from control populations apparently free from malignant disease at the time of the test. An attempt is made to predict the number of unexplained positives, together with the expected age and sex distribution, using published cancer registration statistics. The predicted numbers are compared with the observed numbers of unexplained positives in two clinical trials of the MEM test.     

Effect of tinidazole, metronidazole and nitrofurazone on nucleic acid synthesis in Clostridium bifermentans

Coplanar lines of different orientations rotating in depth and viewed in parallel projection may appear to rotate in different directions and reverse independently of each other, or they may appear coplanar and all reverse together. The frequency of the latter "grouped" appearance for lines with an orientation range of 30 degrees was a function of the number of lines in a given space. Grouping was greater for lines converging to an implicit vanishing point and for lines with collinear edges regardless of their orientations. Line length, and by inference, interline separation also had effect of the nature of the response.