A knowledge-based system for sensor selection

This paper presents a Knowledge-based system (KBS) developed to allow users, who may not be knowledgeable about sensors, to select sensors suitable for their specific needs. The KBS runs on a micro-computer. The selection criteria are user specified and are based on the desired measurement parameters. The system output includes all of the operational and dimensional parameters of the recommended sensor, price, and vendor information.     

Terson''s syndrome in a patient with acute promyelocytic leukemia on all-trans retinoic acid treatment

Hypothermia induced by surface cooling has shown to protect vulnerable regions of the brain during an ischemic insult. This study evaluated the neuroprotective efficacy of neurotensin, a potent hypothermic agent, using a 5-min carotid occlusion procedure in the gerbil. In Experiment 1, the dose-response and time course of neurotensin-induced hypothermia were evaluated (n = 5/dose). Central infusion of 10, 20, and 30 micrograms neurotensin were found to significantly decrease core body temperature of conscious gerbils within 30 min of administration. In Experiment 2, gerbils pretreated with 30 micrograms neurotensin were permitted to become hypothermic or were maintained at 37 degrees-38 degrees C (rectal) during ischemic insult. Other gerbils were pretreated with peptide vehicle prior to ischemic insult (at 37 degrees -38 degrees C) or underwent a sham procedure (n = 6/condition). At 24 h after surgery, gerbils were tested for increased locomotor activity in an open-field apparatus. Gerbils pretreated with peptide vehicle or neurotensin and maintained at 37 degrees-38 degrees C during ischemia had significantly higher activity levels compared to the other treated groups. In contrast, gerbils made hypothermic with neurotensin exhibited activity levels similar to sham gerbils. Histological assessment revealed that neurotensin-induced hypothermia protected the CA1 region from ischemic damage.     

Time jitter analysis of 1-bit sigma-delta synthesizer

This letter presents a general analysis of time jitter in sigma-delta synthesizer. One of the practical applications of 1-bit sigma-delta systems is a generation of high-resolution local oscillator (LO) signals. In order to generate LO signals, one may use a single-bit sigma-delta technique to encode sine waves. Today, direct generation of high-frequency sine wave using a clock with higher frequency, is possible. In this letter, we will analyze different LO signal generators and develop a practical way of computation to decide how to choose the best configuration under minimum degradation of signal-to-noise ratio (SNR) at the output.     

Temperature-dependent diffusion coefficient of soluble substances during ethanol extraction of clove

The temperature dependence of the diffusion coefficient of ethanol-soluble substances from ground cloves (particle size 250 μm) during extraction was estimated by fitting batch extraction data at several temperatures (27.8, 40, 50, and 60°C) to a previously developed mass transfer model. The model was based on spherical geometry of particles. Nonlinear regression analysis was used to develop an equation that describes the diffusivity as a function of temperature. The temperature dependence ofD _A was of the Arrhenius type.     

Graft Copolymerization of Acrylamide onto Oil Palm Empty Fruit Bunch (OPEFB) Fiber

Grafting of acrylamide (AAm) onto oil palm empty fruits bunch fiber using hydrogen peroxide as initiator and methyl acrylate as comonomer was investigated. The amount of comonomer needed to make grafting of acrylamide possible was determined. The percentage of poly(acrylamide) and the comonomer in the final graft copolymer was estimated by elemental analysis. Results obtained indicated that methyl acrylate facilitated the incorporation of acrylamide monomer onto OPEFB. The reactivity ratios for both monomers were determined by using Fineman–Ross plot. The effects of reaction temperature and period as well as amount of the initiator, solvent, monomer and comonomer on the percentage of grafting at fixed amount of comonomer (11 mmol) were studied. Maximum percentage of grafting was achieved when the amount of initiator and solvent 3.98×10⁻³ mol and 50 mL respectively. The optimum reaction temperature was 50 ^○C and the reaction period was 90 min. Highest percentage of grafting was 232% when 25.6 mmol of acrylamide was used under these optimum conditions. The presence of functional group in the grafted polymer is characterized by infrared spectroscopy and the surface morphology is observed by scanning electron microscopy. Thermoanalytic investigation on OPEFB and OPEFB-g-PAAM were carried out to evaluate the thermal stability and respective activation energy of the materials.     

Effect of competitive interference on the biosorption of lead(II) by Chlorella vulgaris

Batch experiments were carried out to asses the effect of Cu(II) and Zn(II) on the biosorption of lead(II) ions by non-living Chlorella vulgaris. The uptake of Pb(II) was examined for single, binary and ternary solutions at different initial concentrations and different pH values. The experimental results showed that the uptake increased with increasing pH from 3.0 to an optimum value of 5.0. The biosorption of Pb(II) was found to be adversely affected by the presence of Cu(II) ions, while Zn(II) ions seemed to have negligible effect on the process. The equilibrium data were fitted to four isotherm models: Langmuir, Freundlich, Sips and Dubinin–Radushkevich; the Sips isotherm gave the best fit for the data. Modeling of the controlling mechanisms indicated that both intrinsic kinetics and mass transfer played major roles in controlling the process. A new dimensionless parameter, Ψ, was defined to asses the relative contributions of the two mechanisms to the biosorption of lead(II). Mass transfer seemed to be the dominant mechanism at low initial lead(II) concentrations, while intrinsic kinetics dominates at high concentrations.     

Effect of kinesthetic and tactile haptic feedback on the quality of experience of edutainment applications

Haptic technologies and applications have received enormous attention in the last decade. The incorporation of haptic modality into multimedia applications adds excitement and enjoyment to an application. It also adds a more natural feel to multimedia applications, that otherwise would be limited to vision and audition, by engaging as well the user’s sense of touch, giving a more intrinsic feel essential for ambient intelligent applications. However, the improvement of an application’s Quality of Experience (QoE) by the addition of haptic feedback is still not completely understood. The research presented in this paper focuses on the effect of haptic feedback and what it potentially adds to the experience of the user as opposed to the traditional visual and auditory feedback. In essence, it investigates certain issues regarding stylus-based haptic education applications and haptic-enhanced entertainment videos. To this end, we used two haptic applications: the haptic handwriting learning tool to experiment with force feedback haptic interaction and the tactile YouTube application for tactile haptic feedback. In both applications, our analysis shows that the addition of haptic feedback will increase the QoE in the absence of fatigue or discomfort for this category of applications. This implies that the incorporation of haptic modality (both force feedback as well as tactile feedback) has positively contributed to the overall QoE for the users.     

An efficient hybrid multicast transport protocol for collaborative virtual environment with networked haptic

In recent years, we have witnessed a growing interest in the synchronous collaboration based class of applications. Several techniques for collaborative virtual environments (CVE), haptic, audio and visual environments (C-HAVE) have been designed. However, several challenging issues remain to be resolved before CVE and C-HAVE become a common place. In this paper, we focus on applications that are based on closely coupled and highly synchronized haptic tasks that require a high-level of coordination among the participants. Four main protocols have been designed to resolve the synchronization issues in such environments: the synchronous collaboration transport protocol, the selective reliable transmission protocol, the reliable multicast transport protocol and the scalable reliable multicast. While these four protocols have shown good performance for CVE and C-HAVE class of applications, none of these protocols has been able to meet all of the basic CVE requirements, i.e., scalability, reliability, synchronization, and minimum delay. In this paper, we present a hybrid protocol that is able to satisfy all of the CVE and C-HAVE requirements and discuss its implementation and results in two tele-surgery applications. This work is partially supported by Grants from Canada Research Chair Program, NSERC, OIT/Ontario Distinguished Researcher Award, Early Research Award and ORNEC Research Grant.     

A multi-objective strategy in genetic algorithms for gene selection of gene expression data

A microarray machine offers the capacity to measure the expression levels of thousands of genes simultaneously. It is used to collect information from tissue and cell samples regarding gene expression differences that could be useful for cancer classification. However, the urgent problems in the use of gene expression data are the availability of a huge number of genes relative to the small number of available samples, and the fact that many of the genes are not relevant to the classification. It has been shown that selecting a small subset of genes can lead to improved accuracy in the classification. Hence, this paper proposes a solution to the problems by using a multiobjective strategy in a genetic algorithm. This approach was tried on two benchmark gene expression data sets. It obtained encouraging results on those data sets as compared with an approach that used a single-objective strategy in a genetic algorithm. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Selecting informative genes from microarray data by using hybrid methods for cancer classification

Gene expression technology, namely microarrays, offers the ability to measure the expression levels of thousands of genes simultaneously in biological organisms. Microarray data are expected to be of significant help in the development of an efficient cancer diagnosis and classification platform. A major problem in these data is that the number of genes greatly exceeds the number of tissue samples. These data also have noisy genes. It has been shown in literature reviews that selecting a small subset of informative genes can lead to improved classification accuracy. Therefore, this paper aims to select a small subset of informative genes that are most relevant for cancer classification. To achieve this aim, an approach using two hybrid methods has been proposed. This approach is assessed and evaluated on two well-known microarray data sets, showing competitive results. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008