Bayesian methods for time‐varying state and parameter estimation in induction machines

This paper addresses the problem of nonlinear time‐varying state and parameter estimation of induction machines (IMs) on the basis of a third‐order electrical model. The objectives of this paper are threefold. The first objective is to propose the use of an improved particle filter (IPF) with better proposal distribution for nonlinear and non‐Gaussian state and parameter estimation. The second objective is to extend the state and parameter estimation techniques (i.e., extended Kalman filter (EKF), unscented Kalman filter (UKF), particle filter (PF), and IPF) to better handle nonlinear and non‐Gaussian processes without a priori state information, by utilizing a time‐varying assumption of statistical parameters. In this case, the state vector to be estimated at any instant is assumed to follow a Gaussian model, where the expectation and the covariance matrix are both random. The third objective is to compare the performances of EKF, UKF, PF, and IPF in estimating the states of the power process model representing the IM (i.e, the rotor speed, the rotor flux, the stator flux, the rotor resistance, and the magnetizing inductance) and their abilities to estimate some of the key system parameters, which are needed to define the IM process model. The results show that the IPF provides a significant improvement over the PF because, unlike the PF, which depends on the choice of sampling distribution used to estimate the posterior distribution, the IPF yields an optimum choice of the sampling distribution, which also accounts for the observed data. This conclusion is also supported by the experimental results. Copyright © 2014 John Wiley & Sons, Ltd.     

Solubility of water in lime-alumina-silica melts

The water solubility in fused silicates of the CaO-SiO₂ and CaO-SiO₂-Al₂O₃ systems has been measured using a vacuum fusion technique. The melts were equilibrated with nitrogen as “carrier gas” containing an accurately known water content. The solubility of water increased on the addition of lime to the melts of both systems. The effect of alumina is initially, to decrease the solubility. Additions above about 20 wt pct at a constant basicity of 0.6 however raised the water solubility of lime-silica melts. From the plot of oxygen density against the hydrogen concentration of the silicate melts of the system lime-silica-alumina studied in this investigation, it may be concluded that free hydroxyls take up interstitial positions in the silicate network. Wustite additions to lime-silica melts of basicity equal to 1 do not appear to influence the water solubility, although the rate of gas absorption from the furnace atmosphere is accelerated significantly. P. L. SACHDEV, formerly Graduate Student, Institut für Eisenhüttenwesen R. W. Technische Hochschule Aachen, West Germany A. MAJDIČ, formerly Senior Engineer, Institut für Eisenhüttenwesen R. W. Technische Hochschule Aachen     

Ménétrier disease associated with a gastric adenocarcinoma. Apropos of 2 cases

PURPOSE: The purpose of this project was to increase use of the Physician Data Query and Patient Information File services of the National Cancer Institute in a clinical setting. OVERVIEW: A patient education demonstration project was conducted at the University of Rochester Cancer Center using a touch-screen computer program called CancerHelp. Two computers were purchased, one stationed in the Patient Library at the University of Rochester Cancer Center and one circulated to three affiliated hospitals. Demographic information was asked at the beginning of the program and an evaluation was elicited at the end of the program. All information was given voluntarily; users of the system could bypass the questions if they wished. The computer program was very well received by patients and their families. The program was used 1758 times over 6 months. CLINICAL IMPLICATIONS: A touch-screen computer program can be an effective method for distributing cancer information.     

Towards an automatic extraction of synonyms for Quranic Arabic WordNet

In this paper, we developed an automatic extraction model of synonyms, which is used to construct our Quranic Arabic WordNet (QAWN) that depends on traditional Arabic dictionaries. In this work, we rely on three resources. First, the Boundary Annotated Quran Corpus that contains Quran words, Part-of-Speech, root and other related information. Second, the lexicon resources that was used to collect a set of derived words for Quranic words. Third, traditional Arabic dictionaries, which were used to extract the meaning of words with distinction of different senses. The objective of this work is to link the Quranic words of similar meanings in order to generate synonym sets (synsets). To accomplish that, we used term frequency and inverse document frequency in vector space model, and we then computed cosine similarities between Quranic words based on textual definitions that are extracted from traditional Arabic dictionaries. Words of highest similarity were grouped together to form a synset. Our QAWN consists of 6918 synsets that were constructed from about 8400 unique word senses, on average of 5 senses for each word. Based on our experimental evaluation, the average recall of the baseline system was 7.01 %, whereas the average recall of the QAWN was 34.13 % which improved the recall of semantic search for Quran concepts by 27 %.     

RecAm: a collaborative context-aware framework for multimedia recommendations in an ambient intelligence environment

With an ever-increasing accessibility to different multimedia contents in real-time, it is difficult for users to identify the proper resources from such a vast number of choices. By utilizing the user’s context while consuming diverse multimedia contents, we can identify different personal preferences and settings. However, there is a need to reinforce the recommendation process in a systematic way, with context-adaptive information. The contributions of this paper are twofold. First, we propose a framework, called RecAm, which enables the collection of contextual information and the delivery of resulted recommendation by adapting the user’s environment using Ambient Intelligent (AmI) Interfaces. Second, we propose a recommendation model that establishes a bridge between the multimedia resources, user joint preferences, and the detected contextual information. Hence, we obtain a comprehensive view of the user’s context, as well as provide a personalized environment to deliver the feedback. We demonstrate the feasibility of RecAm with two prototypes applications that use contextual information for recommendations. The offline experiment conducted shows the improvement of delivering personalized recommendations based on the user’s context on two real-world datasets.     

Determining the effects of thermal conductivity on epoxy molds using profiled cooling channels with metal inserts

Polymer injection molds are generally manufactured with metallic materials, such as tool steel, which provide reliable working of molds and extended service life. The manufacture of injection molds with steel is a prolonged process because of the strength of steel. For a short prototype production run, one of the suitable choices could be the use of aluminum-filled epoxy material, which can produce a functional mold in a short time as compared with a conventionally machined tool. Aluminum-filled epoxy tooling is a good choice for short production runs for engineering applications, yet works best for relatively simple shapes. The advantages in relation to the fabrication of injection molds with epoxy-based materials include time saving in producing the mold, epoxy curing at ambient temperature, and ease of machining and post processing. Nevertheless, one major drawback of epoxy material is its poor thermal conductivity, which results in a relatively longer cooling time for epoxy injection molds. This study investigates some of the innovative ideas for enhancing the thermal conductivity for epoxy molds. The basic concept behind these ideas was to embed a highly thermally conductive metal insert within the mold between cavities with an innovative design of cooling channels called profiled cooling channels. This technique will increase the effective thermal conductivity of the epoxy mold, leading to the reduction in cooling time for the injection molded polymer part. Experimental analysis conducted in the current study also verified that the mold with profiled cooling channels and embedded metal insert has significantly reduced the cooling time.