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One of the many strengths of the Rescorla and Wagner (1972) model is that it accounts for both excitatory and inhibitory learning using a single error-correction mechanism. However, it makes the counterintuitive prediction that nonreinforced presentations of an inhibitory stimulus will lead to extinction of its inhibitory properties. Zimmer-Hart and Rescorla (1974) provided the first of several animal conditioning studies that contradicted this prediction. However, the human data are more mixed. Accordingly, we set out to test whether extinction of an inhibitor occurs in human causal learning after simultaneous feature negative training with a conventional unidirectional outcome. In 2 experiments with substantial sample sizes, we found no evidence of extinction after presentations of the inhibitory stimulus alone in either a summation test or causal ratings. By contrast, 2 "no-modulation" procedures that contradicted the original training contingencies successfully reversed inhibition. These results did not differ substantially as a function of participants' self-reported causal structures (configural/modulation/prevention). We hypothesize that inhibitory learning may be intrinsically modulatory, analogous to negative occasion-setting, even with simultaneous training. This hypothesis would explain why inhibition is reversed by manipulations that contradict modulation but not by simple extinction, as well as other properties of inhibitory learning such as imperfect transfer to another excitor. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Inhibitory learning after feature negative training (A+/AB-) is typically measured by combining the Feature B with a separately trained excitor (e.g., C) in a summation test. Reduced responding to C is taken as evidence that B has properties directly opposite to those of C. However, in human causal learning, transfer of B's inhibitory properties to another excitor is modest and depends on individual differences in inferred causal structure. Here we ask whether instead of opposing processes, a summation test might instead be thought of in terms of generalization. Using an allergist task, we tested whether inhibitory transfer would be influenced by similarity. We found that transfer was greater when the test stimuli were from the same semantic category as the training stimuli (Experiments 1 and 2) and when the test excitor had previously been associated with the same outcome (Experiment 3). We also found that the similarity effect applied across all self-reported causal structures. We conclude it may be more helpful to consider transfer of inhibition as a form of conceptual generalization rather than the arithmetic summation of opposing processes. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Beliefs about cause and effect, including health beliefs, are thought to be related to the frequency of the target outcome (e.g., health recovery) occurring when the putative cause is present and when it is absent (treatment administered vs. no treatment), this is known as contingency learning. However, it is unclear whether unvalidated health beliefs, where there is no evidence of cause–effect contingency, are also influenced by the subjective perception of a meaningful contingency between events. In a survey, respondents were asked to judge a range of health beliefs and estimate the probability of the target outcome occurring with and without the putative cause present. Overall, we found evidence that causal beliefs are related to perceived cause–effect contingency. Interestingly, beliefs that were not predicted by perceived contingency were meaningfully related to scores on the paranormal belief scale. These findings suggest heterogeneity in pseudoscientific health beliefs and the need to tailor intervention strategies according to underlying causes.

Background: Consumption of sugar-sweetened beverages (SSBs) forms the primary source of added sugar intake and can increase the risk of metabolic disease. Evidence from studies in humans and rodents also indicates that consumption of SSBs can impair performance on cognitive tests, but that removing SSB access can ameliorate these effects. Methods: The present study used an unblinded 3-group parallel design to assess the effects of a 12-week intervention in which young healthy adults (mean age = 22.85, SD = 3.89; mean BMI: 23.2, SD = 3.6) who regularly consumed SSBs were instructed to replace SSB intake with artificially-sweetened beverages (n = 28) or water (n = 25), or (c) to continue SSB intake (n = 27). Results: No significant group differences were observed in short-term verbal memory on the Logical Memory test or the ratio of waist circumference to height (primary outcomes), nor in secondary measures of effect, impulsivity, adiposity, or glucose tolerance. One notable change was a significant reduction in liking for strong sucrose solutions in participants who switched to water. Switching from SSBs to ‘diet’ drinks or water had no detectable impact on cognitive or metabolic health over the relatively short time frame studied here. This study was prospectively registered with the Australian New Zealand Clinical Trials Registry (ACTRN12615001004550; Universal Trial Number: U1111-1170-4543).

When laboratory rats are given repeated access to an activity wheel, the amount that they run steadily increases. This suggests an analogy with drug dependency in animals and humans, in that this is marked by both increasing intakes of the drug and increasing motivation to obtain the drug (craving). This analogy was examined by measuring motivation to obtain an opportunity to run using a progressive ratio (PR) schedule, whereby the number of lever presses required to release a brake on an activity wheel was increased progressively. Each of two experiments included two groups of rats that differed in running experience. In Experiment 1, both groups were given 17 wheel-running sessions before they were given the PR test, with sessions for the short group lasting only 30 min, while those for the long group lasted 4.5 hrs. In Experiment 2, both groups were given 3-hr wheel sessions, with the short group given only four such sessions and the medium groups given 12 such sessions prior to their PR test. In both experiments, the PR tests revealed that motivation to run was greater when the rats had not had an opportunity to run for at least 24 hrs prior to the test than when they had run the previous day. However, neither experiment produced evidence that motivation to run increased with the amount of previous running. Given only limited support for the analogy between running and drug addiction, steady increases in running may instead reflect circadian adaptation and/or increases in fitness.

It is estimated that 50% of Canadian households are directly or indirectly affected by food allergies. Since accidental exposure to food allergens can cause life-threatening reactions, the need for accurate allergen labelling is key. In Canada, new food allergen labelling guidelines were mandated in August 2012. While a substantial improvement, gaps remain. This study explored the perspectives of directly affected individuals as well as members of the general public regarding their needs and preferences for precautionary labelling, allergen symbols, and suggestions for improving labelling practices in Canada. Eight qualitative focus groups were conducted with directly affected (n=27) and general public (n=24) consumers in Vancouver, Canada. Focus groups were audio recorded and transcribed verbatim for subsequent thematic analysis using NVivo9. Although "may contain" is recommended by Health Canada, it was the least preferred precautionary statement among research participants. Both participant groups described how many consumers' purchasing habits are indirectly affected by food allergy; hence, their views should be considered in addition to those of directly affected individuals when developing allergen labelling policies. The findings identify future policy needs: 1) mandating and standardizing precautionary/allergen statements and symbols, 2) increased monitoring, and 3) increasing food allergy education and awareness among consumers and manufacturers.

A power/ground plane pair is proposed using a novel planar electromagnetic bandgap (EBG) structure for isolating the power-to-ground noise (PGN) in high-speed circuits. Each unit cell of the novel EBG is designed by etching slots in a “C” shape on the power plane while maintaining the ground plane solid. Without cascading hybrid periodic structures, it shows an efficient mitigation of PGN within an ultra-wideband frequency range of 0.25-2.18 GHz. In this paper, the equivalent circuit model and cavity mode analysis for the novel EBG unit cell are given to quickly predict the lower and upper bound cutoff frequency, respectively. The dispersion diagram of the proposed EBG structure is validated by insertion loss measurements with ports at different locations of the unit cell for different modes. The result shows that there is a good consistency between the simulated and measured results.

In this study, CO2 laser was used for treating cotton fabric to create surface effects which were found to vary with laser process parameters, i.e. resolution and pixel time. The resolutions used were 40, 50 and 60 dpi while the pixel time used were 100, 110 and 120 μs. Both physical and chemical properties at the surface of fabrics treated with different combinations of resolution and pixel time were analysed by the Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy with Attenuated Total Reflection mode (FTIR-ATR), and X-ray Photoelectron Spectroscopy (XPS). SEM investigation revealed the appearance of various numbers of pores, cracks and fragments present on the fibre surface after laser treatment. FTIR-ATR spectra showed that the laser-treated cotton fabric suffered changes in chemical structure with the hydroxyl (–OH) stretching group being oxidised to carbonyl/carboxyl groups. The XPS analysis revealed a change in surface elemental composition after laser treatment. Furthermore, the wicking property of the laser-treated cotton fabrics was evaluated.

The surface morphology of the CO2 laser treated grey cotton fabrics was studied which showed a characteristics sponge-like structure on cotton fibres after treating with CO2 laser irradiation. The laser treatment parameters ranging from 100 to 150 pixel time and 40 to 70 dot per inch (dpi) were irradiated on the grey cotton fabrics directly and the degree of physical modifications, such as surface morphology, wettability and fabric strength, were changed accordingly with various laser treatment parameters. The surface morphology, wettability and tensile strength of cotton fibre treating with laser were evaluated using different instruments, such as Scanning Electron Microscope (SEM), contact angle meter and tensile strength machine. In spite of creating a sponge-like structure on fibre surface after treating with laser, the wettability of the samples was highly improved but the tensile strength was decreased.

In this paper, the effect of sun protection agent on different hair samples including, (i) unbleached hair sample, (ii) bleached hair sample and (iii) bleached hair sample with subsequent hair coloration, were studied. This paper was aimed at evaluating the effectiveness of sun protection agent on the different hair conditions. The hair samples were divided into two sets; one was the samples applied with sun protection agent, while the other one was without the application of sun protection agent. The results of colour change were evaluated by means of CIE L*a*b* values of samples and the tensile strength of hair was measured using tensile testing machine. In the case of colour change, the overall results showed that there was a decrease in colour change when the sunlight exposure time was prolonged. At the same time, the hair samples treated with the sun protection agent could provide a lower change in colour than the hair samples without the sun protection agent. With respect to the tensile strength properties, the results obtained indicated that the breaking load of treated samples decreased when the sunlight exposure time was prolonged. The change in tensile strength of the samples treated with the sun protection agent was smaller than the hair samples without the sun protection agent. In addition, the results indicated that the coloration process did not further decrease the tensile strength of hair samples.

In this paper, detailed simulation of human hair bleaching was conducted. The materials and chemical used as well as the hair bleaching procedures were described. After bleaching, the colour change of the hair was evaluated in accordance with CIE Lab system and the hair bleaching results was analysed. Following the hair bleaching process, hair coloration was employed with the use of colour boosting shampoo with henna of three different colours. The effect of different bleached hair samples on colour uptake property was examined by spectrophotometer method. Based on this study, it was concluded that the original hair colour did affect the colour uptake using the colour boosting shampoo with henna significantly. In order to have a visible coloring result, hair bleaching treatment was therefore highly recommended before conducting the hair coloration process.

An H-plane horn antenna constructed into SIW (substrate integrated waveguide) is proposed. It has a dielectric arc lens for better directivity and a simple microstrip transition as feed. The horn, the lens and the transition share the same substrate. The resulting formula from optical principles shows that the suitable dielectric lens can improve the directivity of the antenna significantly. A prototype was fabricated; the antenna size is 39.175 × 14 × 2 mm3. The frequency band is from 25.5 to 28.5 GHz. The measured gain of this antenna is about 9 dB; the bandwidth, at 10 dB return loss, is over 12%. © 2007 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2007.

This paper derives simple computer-aid design (CAD) formulas of the components of the equivalent circuit of square spiral inductors on a microstrip substrate. The circuit components are the main inductor, its capacitors to ground, and resistance. The formulas are simple synthetic asymptotes constructed from duality and analytical moment method, and give clear physical insights. Compared with IE3D, a commercial software by Zeland, the errors of |S 11| and |S 21| are generally less than 2%.

Accurate CAD formulas of a microstrip line on a ground plane with periodic perforations, closely spaced and at quasistatic frequencies, are derived (error

A rapid and accurate approach is developed to solve the response of an irregularly shaped patch. This approach is based on the observation that the actual irregularly shaped patch can usually be taken as a perturbation of a regularly shaped patch. The steps of the approach are: 1) ideal regular patch (square), 2) irregular patch (corner cut), 3) add fringe field perturbation, and 4) Cauchy's interpretation. Results with less than 0.3% error in resonant frequency are obtained. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 70–74, 2001.

Double-sided parallel strip line (DSPSL) is a versatile microwave transmission line. With an offset, it allows for large variations of the characteristic impedance and therefore flexibility for the design of novel microwave devices. In this letter, a formula for the characteristic impedance of DSPSL is derived by the fuzzy EM method and verified by commercial software. Very good agreement is observed.

Traditional impedance measurement of a monopole antenna is inaccurate due to a likely stray radiating current on the measuring cable that is also affected by the operating human. This letter demonstrates experimentally that the elimination of this stray current is possible by using a special sleeve balun suitable for varied PCB ground-plane and human postures. Adjustment of the balun position is discussed. ©1999 John Wiley & Sons, Inc. Microwave Opt Technol Lett 23: 349–352, 1999.

A grounding system is on one of the most important points inside transmission and power distribution systems. Poor design methods and simplified calculations can lead to high construction costs and unsafe conditions. This paper introduces a method to design a grounding grid while minimizing time and cost of construction. In this work, computer software has been developed using the equations to solve the optimization problem that considers the parameters of a grounding grid, including geometry, depth, conductor size and the number of grounding rods. The problem is formulated as a mixed integer linear optimization problem. The method incorporates the variables that define the grid characteristics of all possible configurations, including the grid geometry, grid depth, conductor size, and number of grounding rods, size of grounding rods, and, lastly, excavation and installation costs. The optimization problem is subject to safety constraints related to the maximum allowed ground potential rise (GPR), touch and step voltages. The method determines the optimum grid from several possible configurations, so that is a very useful tool for engineering design. A novel optimization technique using a random walk technique to find an optimized grounding grid in a two-layer soil model is proposed. Several examples prove the efficacy of the method.

This paper derives a pair of simple analytical formulas for the Sunde curves, which are then used to determine a two-layer soil model through numerical optimization. Sunde's curves were effectively generated from an infinite series of multiple images in two-layer soil, but in this paper are replaced by their asymptotes. Simplicity provides confidence in the soil model constructed, which will lead to better ground grid design, and the possibility in the future of extending the soil model into 3 or even more layers. The simplicity of the formulas is also found to make the optimization process of the soil determination much faster than previous methods, and yet the accuracy is found to be equal or even slightly better.

The induced charge on a grounded arbitrary conductor, excited by a nearby point charge, is shown to be approximated by that on an equivalent conducting sphere near the same point charge. The proof is modified from that for capacitance by Payne and Weinberger [J. Math. Phys. 33, 291 (1955)]. A number of examples for different grounded blocks and plate are given. The potential field distributions from the induced charge are also given.

In this paper, the complex image method is used to model ground electrodes in layered soils. The image locations and amplitudes are determined through a simple Prony method [R. W. Hamming, Numerical Methods for Scientists and Engineers (Dover, New York, 1973), pp. 620–622]. As an example, a toroidal electrode in a four‐layer soil is modeled using one real image and four complex images. The results obtained are identical to those reported recently in the literature, given by more than 10 000 images using the conventional electrostatic image method.

In this letter, an approximate time-domain Green's function of a microstrip structure is presented, and is applied to analyze an electrically thin microstrip transmission line. Numerical examples show that the approximate time-domain Green's function is effective. © 2000 John Wiley & Sons, Inc. Microwave Opt Technol Lett 25: 423–425, 2000.

The high-frequency skin-depth approximation for ohmic loss calculations is not valid if the conductor thickness decreases and approaches the skin depth. This is the situation in many monolithic microwave integrated circuits (MMICs). The two asymptotes of loss, at dc and at high frequency of the above, are, in fact, known. This letter constructs a single synthetic asymptote that joins the two original asymptotes, and gives good loss values at intermediate frequencies where the above skin depth occurs, not unlike a French curve fitting. ©1999 John Wiley & Sons, Inc. Microwave Opt Technol Lett 20: 302–304, 1999.

This paper discusses the use of the Hidden Markov Model (HMM) in phonetic recognition. In particular, we present improvements that deal with the problems of modeling the effect of phonetic context and the problem of robust pdf estimation. The effect of phonetic context is taken into account by conditioning the probability density functions (pdfs) of the acoustic parameters on the adjacent phonemes, only to the extent that there are sufficient tokens of the phoneme in that context. This partial conditioning is achieved by combining the conditioned and unconditioned pdfs models with weights that depend on the confidence in each pdf estimate. This combination is shown to result in better performance than either model by itself. We also show that it is possible to obtain the computational advantages of using discrete probability densities without the usual requirement for large amounts of training data.

This paper describes the results of our work in designing a system for phonetic recognition of unrestricted continuous speech. We describe several algorithms used to recognize phonemes using context-dependent Hidden Markov Models of the phonemes. We present results for several variations of the parameters of the algorithms. In addition, we propose a technique that makes it possible to integrate traditional acoustic-phonetic features into a hidden Markov process. The categorical decisions usually associated with heuristic acoustic-phonetic algorithms are replaced by automated training techniques and global search strategies. The combination of general spectral information and specific acoustic-phonetic features is shown to result in more accurate phonetic recognition than either representation by itself.

Knowledge of mutual coupling between antennas is of much importance for the design of practical antenna arrays of finite size. This paper constructs a formula for mutual impedance between patch antennas based on the physics of the static near field coupling and of the far field radiation couplings, i.e., the near and far asymptotes. The two asymptotes are then combined to form a synthetic asymptote [1], of separated variables of the center-to-center distance r and the azimuth angle ϕ. Only 12 coefficients are to be determined by matching with a full wave analysis with commercial software, such as IE3D. Our formula is complete with no restriction on the detailed structures of patch, feed and substrate.

Like the field computation of capacitance, thermal resistance from an ICs is normally done by simulating over a very large region of the device and substrate, in 3D and with very fine meshing. This is especially necessary in a temperature dependent substrate such as GaAs [1]. Through the root-of-area capacitance formula of the electrical equivalent, this paper shows that the tedious 3D fine meshing may be replaced by a simple equivalent circuit.

This paper gives a simple CAD formula for inductance of square spiral inductor with grounded substrate, by duality and synthetic asymptote. The average error of the formula is less than 2%. The formula also gives good physical insights to the layout design of the inductor spiral.

Three methods for smoothing discrete probability functions in discrete hidden Markov models for large-vocabulary continuous-speech recognition are presented. The smoothing is based on deriving a probabilistic co-occurrence matrix between the different vector-quantized spectra. Each estimated probability density is then multiplied by this matrix, ensuring that none of the probabilities are severely underestimated due to lack of training data. Experimental results show a 20-30% reduction in error rate when this smoothing is used. A word error rate of 3.0% is achieved with the DARPA 1000-word continuous speech recognition database and a word-pair grammar with a perplexity of 60. >

The authors describe a system for speech understanding that uses hidden Markov models for acoustic modeling, a unification grammar for the syntax of English, and a higher order intensional logic for semantic representation. To maximize speech understanding performance, the constraints of the linguistic models must be used in the search for the most likely interpretation of the spoken message. The basic approach is to perform parsing (as in natural language processing) on the word lattice input produced by a lattice engine. The authors present two lattice parsing algorithms that determine a list (ordered by acoustic likelihood) of word sequences allowed by the grammar and present in the lattice. They describe how semantic constraints can be applied a posteriori to find the most likely interpretation of the input speech. They give speech understanding results on the standard DARPA resource management speech database. >

A search algorithm that provides a simple, clean, and efficient interface between the speech and natural language components of a spoken language system is introduced. The N-best algorithm is a time-synchronous Viterbi-style beam search procedure that is guaranteed to find the N most likely whole sentence alternatives that are within a given beam of the most likely sentence. The computation is linear with the length of the utterance, and faster than linear in N. When used together with a first-order statistical grammar, the correct sentence is usually within the first few sentence choices. The output of the algorithm, which is an ordered set of sentence hypotheses with acoustic and language model scores can easily be processed by natural language knowledge sources without the huge expansion of the search space that would be needed to include all possible knowledge sources in a top-down search. In experiments using a first-order statistical language model, the average rank of the correct answer was 1.8 and was within the first 24 choices 99% of the time. >

An application of discriminative training methods, maximum mutual information (MMI) training, to large-vocabulary continuous speech recognition is described. An algorithm is developed for efficient MMI estimation of HMM parameters, including exponential codebook coefficients, which cannot be estimated using maximum likelihood (ML) methods. Continuous speech recognition performance of the BYBLOS system on the DARPA 1000-word resource management speech corpus is presented. >

This development starts from a simplified (fuzzy) formulation and continues with derivations leading to desired CAD formulas of practical circuit components. Because of the simplification at the beginning, the derivation and the formula can be rigorous but remain simple at the same time. Simplification is applied only once still, at the beginning of the derivation. Therefore the error resulted is not larger than that of regular methods, analytical or numerical. Many examples of simple and insightful CAD formulas are given in this paper.

Integrated circuits for digital, microwave and optical purposes are fabricated on layered medium substrates. The simulated image technique is an efficient tool for modeling electromagnetic phenomena in layered medium structures. In this paper, we present the discrete complex image theory which finds the simulated images of a source in multilayered media. A critical comparison is made between the discrete complex image theory and other published image theories, i.e., the exact image theory based on the Laplace transformation of the spectral function, and the approximate image theory based on the Taylor expansion of the spectral function.

Like the classical charge image method, the optimized simulated image method gives very simple expressions for the capacitance of a conducting body and the potential field around it. Unlike the former method, however, it can be applied to arbitrary conducting bodies. Also, the simple expressions for the potential field are found to be well suited for calculating the capacitance bounds of Payne and Weinberger. These two nice properties are derived, and are demonstrated by examples. The examples are the capacitance of (i) a conducting cube and (ii) a series of conducting cylinders of finite lengths.

As an aid to the study of coupling microstrip structures, this paper analyzes and computes the radial dependence, along the dielectric substrate, of the magnetic field Green’s function of a horizontal magnetic dipole. The analysis is based on the contour integration of the exact spectral Green’s function. From the results, it is observed that the radial dependence can easily be approximated by the corresponding free‐space Green’s function with a small correction term.

A simple method of calculating corona loss on a unipolar dc transmission line, without a ground wire, is presented in this paper. The simplification occurs due to the avoidance of double integration involved in Sarma and Janischewskyj's [1] method and also due to a justifiable linear approximation of the corona current density on the conductor surface for this simple geometry. The computer program has less than 100 statements and the typical computation time involved in plotting a V-I characteristic is less than 4 seconds on an IBM 370/145 computer. The error in the computed results, due to the above simplifications, is less than 1%.

The aminium radicals generated from the photolysis of N-nitroso-endo-2-methylamino-methylbicyclo[2.2.1]hept-5-en and N-nitroso-endo-2-methylaminomethylbicyclo[2.2.2]oct-5-ene cyclize at the C-6 position, since the relevant reacting centers can achieve excellent orbital overlap with minimum molecular motion in comparison to the alternative cyclization path at the C-5 position. The photolysis of the former compound gave a C-nitroso compound which underwent a series of unusual intramolecular cleavages, deoximations, and redox reactions during the work-up. Stereoelectronic requirements for these intramolecular reactions are discussed. Thermolysis of N-chloro-endo-2-methylaminomethylbicyclo[2.2.2]oct-5-en in methanol also gave the product with azaisotwistane skeleton.

Laser Raman spectroscopy was used to monitor changes in the substitution pattern during the formation of a phenol–formaldehyde resin (resol). The substitution-sensitive bands were identified and their relative intensities related to molecular weight of the resol. Results of this study are similar to those obtained by previous workers in the field using paper chromatography. The absorbance ratio of 784-cm−1 to 998-cm−1 bands was found to be linearly related to the molecular weight of the resol.

This paper shows, analytically and numerically, that the capacitance is a slowly changing function of the conductor shape. This slow change can be monitored by a ‘‘shape factor’’ which is independent of the conductor size. Because of this slow change, from the tabulation of the shape factor, the capacitance of many conductors of arbitrary sizes and shapes with both convex and concave surfaces, can be estimated to an error of 5% or less.