Temporal loudness weights: Primacy effects, loudness dominance and their interaction

Loudness judgments of sounds varying in level across time show a non-uniform temporal weighting, with increased weights assigned to the beginning of the sound (primacy effect). In addition, higher weights are observed for temporal components that are higher in level than the remaining components (loudness dominance). In three experiments, sounds consisting of 100- or 475-ms Gaussian wideband noise segments with random level variations were presented and either none, the first, or a central temporal segment was amplified or attenuated. In Experiment 1, the sounds consisted of four 100-ms segments that were separated by 500-ms gaps. Previous experiments did not show a primacy effect in such a condition. In Experiment 2, four- or ten-100-ms-segment sounds without gaps between the segments were presented to examine the interaction between the primacy effect and level dominance. As expected, for the sounds with segments separated by gaps, no primacy effect was observed, but weights on amplified segments were increased and weights on attenuated segments were decreased. For the sounds with contiguous segments, a primacy effect as well as effects of relative level (similar to those in Experiment 1) were found. For attenuation, the data indicated no substantial interaction between the primacy effect and loudness dominance, whereas for amplification an interaction was present. In Experiment 3, sounds consisting of either four contiguous 100-ms or 475-ms segments, or four 100-ms segments separated by 500-ms gaps were presented. Effects of relative level were more pronounced for the contiguous sounds. Across all three experiments, the effects of relative level were more pronounced for attenuation. In addition, the effects of relative level showed a dependence on the position of the change in level, with opposite direction for attenuation compared to amplification. Some of the results are in accordance with explanations based on masking effects on auditory intensity resolution.

The influence of accidental physical contacts between individuals on viral infection

The paper is devoted to the results of numerical modelling of non-stationary effects during the spread of a viral infection in a small group of individuals. We are considering the case of the spread of a viral infection by airborne droplets. Two consecutive stages of infection of the body are considered. At the first stage, virions enter the lungs and as a result of viremia are transported to the affected organs. In the second stage, the virions actively replicate in the affected organs. Random movement of individuals in the group changes the local concentration of virions near the selected individual. The random level of virion concentration may be greater than a certain critical value after which the infection of the selected individual will go into an irreversible stage. The main purpose of our work is to illustrate qualitatively new effects that occur in nonlinear systems in a random environment.

Evaluation of tractor driving comfort according to the steering angle and speed using a virtual prototype

As tractors mainly transit rural roads, drivers can suffer from harmful vibrations transmitted though their seats. Thus, the driving comfort in tractors with agricultural equipment should be evaluated. To investigate the effects of forward motion and front-wheel steering on the driving comfort of two-wheel-drive tractors with agricultural equipment, we establish a man–machine–road virtual prototype for simulations and validate it experimentally. First, a tractor that has suspended agricultural equipment and is operating at front-wheel steering angles of 0°, 12°, 24°, and 36° is driven on a random level-D road. Simultaneously, the vibration accelerations experienced by the driver are obtained along the X, Y, and Z axes with the coordinate system defined according to the ISO 2631-1 standard. The combined weighted root-mean-square (RMS) acceleration corresponding to the driver’s whole-body vibration increases from 0.205 to 0.909 m/s2 when increasing the steering angle. Then, considering the forward speed as the variable, the front-wheel steering angle is set at 30°, and the vibration accelerations experienced by the driver are obtained when the tractor travels at 4, 5, and 6 km/h on a random level-D road. The combined weighted RMS acceleration corresponding to the driver’s whole-body vibration increases from 0.68 to 1.03 m/s2 when increasing the speed. Therefore, we found that the velocity of a tractor should be reduced while steering, and excessively large front-wheel steering angles should be avoided to increase driving comfort.

Do descendants of families contribute to type 2 diabetes mellitus?

Diabetes is a public health problem in Indonesia that has been increasing in recent decades. Screening for diabetes was usually identified as pregnant women, adolescents, adults, children, older and obesity, while based on investigation descendent was yet. This cross-sectional study aimed to know the random level blood glucose of family history type 2 diabetes mellitus (T2DM). The target group for screening was people with a family history in one of their descent of T2DM with age >20 years in Kulon Progo, DIY, Indonesia. We conducted a detection of random level blood glucose from a venous blood sample. A high level of blood glucose was diagnosed when random blood glucose reaches ≥200 mg/dl. The participant with high level of blood glucose was 29.0%, while borderline blood glucose (≥110-199 mg/dl) was revealed 38.7% of 15.3% subject indicated with mother history. Descendant screening of family history T2DM is early detected respondent with high glucose level and reduced the severe complication.

Modeling Volatility of Asset and Volume of Trade Returns in the Nigerian Stock Market in the Presence of Random Level Shifts

This study investigated the impact of volatility shock persistence on the conditional variance in the Nigerian stock returns using symmetric and asymmetric higher order GARCH family models in the presence of random level shifts and non-Gaussian errors. The study utilised Bai and Perron methodology to detect structural breakpoints in the conditional variance of daily stock and volume of trade returns in the Nigerian stock market from 2nd January, 1998 to 22nd March, 2017. The study employed symmetric GARCH (3,2) and GARCH (2,1)-M models to estimate volatility of asset returns, symmetric GARCH (2,2) and GARCH (2,1)-M to model volatility of volume of trade returns and asymmetric EGARCH (2,2), TGARCH (3,2) and PGARCH (2,3) models to measure the volatility of asset returns as well as asymmetric EGARCH (2,1), TGARCH (1,3) and PGARCH (3,2) models to estimate volatility of volume of trade returns. These models were optimally selected using information criteria and log likelihood as the best fitting symmetric and asymmetric GARCH models to estimate the conditional volatility of asset and volume of trade returns in the Nigerian stock market with and without structural breaks. Results revealed that when random level shifts were ignored in volatility models, the shocks persistence were very high with long memory and variance explosion. But when the random level shifts were incorporated into the GARCH models, there was a significant reduction in the volatility shocks persistence and long memory. Moreover, volatility half-lives also declined drastically while accounting for these sudden level shifts in variance. The study found asymmetry without leverage effects as well as a positive risk-return tradeoff for both asset and volume of trade returns in the Nigerian stock market. The Nigeria banking reform of 2004, the Global Financial and Economic Crises, as well as other local events in Nigeria, were found to have negative and significant impacts on the Nigerian stock market. The study provided some policy recommendations.

How much market making does a market need?

We consider a simple model for the evolution of a limit order book in which limit orders of unit size arrive according to independent Poisson processes. The frequencies of buy limit orders below a given price level, respectively sell limit orders above a given level, are described by fixed demand and supply functions. Buy (respectively, sell) limit orders that arrive above (respectively, below) the current ask (respectively, bid) price are converted into market orders. There is no cancellation of limit orders. This model has been independently reinvented by several authors, including Stigler (1964), and Luckock (2003), who calculated the equilibrium distribution of the bid and ask prices. We extend the model by introducing market makers that simultaneously place both a buy and sell limit order at the current bid and ask price. We show that introducing market makers reduces the spread, which in the original model was unrealistically large. In particular, we calculate the exact rate at which market makers need to place orders in order to close the spread completely. If this rate is exceeded, we show that the price settles at a random level that, in general, does not correspond to the Walrasian equilibrium price.