A QUASISTATIC FRICTIONAL CONTACT PROBLEM WITH NORMAL DAMPED RESPONSE FOR THERMO-ELECTRO-ELASTIC-VISCOPLASTIC BODIES

We consider a mathematical problem for quasistatic contact between a thermo-electro--elastic-viscoplastic body and an obstacle. The contact is modeled by a general normal damped response condition with friction law and heat exchange. We present a variational formulation of the problem and prove the existence and uniqueness of the weak solution. The proof is based on the formulation of four intermediate problems for the displacement field, the electric potential field and the temperature field, respectively. We prove the unique solvability of the intermediate problems, then we construct a contraction mapping whose unique fixed point is the solution of the original problem.

Computer intelligent dynamic simulation and optimization for structural platform of water treatment subsystem on the spacecraft

In order to reduce the load response condition of space-borne equipment, an optimized design scheme of carbon fiber composites sandwich panel was proposed in this paper. The state before and after optimization was analyzed and compared trough simulation calculation. The comparison shows that after the honeycomb sandwich structure was optimized, its fundamental frequency increased by 75%, the drawing force of embedded parts decreased by 50%, and the maximum acceleration response also decreased. Finally, the response under sinusoidal vibration was evaluated by test, and the results show that the optimization of the structure is reasonable and feasible, it can be the reference of other similar products.

Age-related increases in reaction time result from slower preparation, not delayed initiation

Recent work indicates that healthy younger adults can prepare accurate responses faster than their voluntary reaction times indicate, leaving a seemingly unnecessary delay of 80-100ms before responding. Here we examined how the preparation of movements, initiation of movements, and the delay between them are affected by age. Participants made planar reaching movements in two conditions. The "Free Reaction Time" condition assessed the voluntary reaction times at which participants responded to the appearance of a stimulus. The "Forced Reaction Time" condition assessed the minimum time actually needed to prepare accurate movements by controlling the time allowed for movement preparation. The time taken to both initiate movements in the Free Reaction Time and to prepare movements in the Forced Response condition increased with age. Notably, the time required to prepare accurate movements was significantly shorter than participants' self-selected initiation times; however, the delay between movement preparation and initiation remained consistent across the lifespan (~90ms). These results indicate that the slower reaction times of healthy older adults are not due to an increased hesitancy to respond, but can instead be attributed to changes in their ability to process stimuli and prepare movements accordingly, consistent with age-related changes in brain structure and function.

Brain reactivity during aggressive response in women with premenstrual dysphoric disorder treated with a selective progesterone receptor modulator

Premenstrual dysphoric disorder (PMDD) is a psychiatric condition characterized by late luteal phase affective, cognitive, and physical impairment. The disorder causes significant suffering in about 5% of women in their reproductive age. Altered sensitivity of cognitive-affective brain circuits to progesterone and its downstream metabolite allopregnanolone is suggested to underlie PMDD symptomatology. Core mood symptoms include irritability and anger, with aggression being the behavioral outcome of these symptoms. The present study sought to investigate the neural correlates of reactive aggression during the premenstrual phase in women with PMDD, randomized to a selective progesterone receptor modulator (SPRM) or placebo. Self-reports on the Daily Record of Severity of Problems were used to assess PMDD symptoms and gonadal hormone levels were measured by liquid chromatography tandem mass spectrometry. Functional magnetic resonance imaging was performed in 30 women with PMDD, while performing the point subtraction aggression paradigm. Overall, a high SPRM treatment response rate was attained (93%), in comparison with placebo (53.3%). Women with PMDD randomized to SPRM treatment had enhanced brain reactivity in the dorsal anterior cingulate cortex and dorsomedial prefrontal cortex during the aggressive response condition. The fronto-cingulate reactivity during aggressive responses depended on treatment, with a negative relationship between brain reactivity and task-related aggressiveness found in the placebo but not the SPRM group. The findings contribute to define the role of progesterone in PMDD symptomatology, suggesting a beneficial effect of progesterone receptor antagonism, and consequent anovulation, on top-down emotion regulation, i.e., greater fronto-cingulate activity in response to provocation stimuli.

A New Class of History–Dependent Evolutionary Variational–Hemivariational Inequalities with Unilateral Constraints

In this paper we study a new abstract evolutionary variational–hemivariational inequality which involves unilateral constraints and history–dependent operators. First, we prove the existence and uniqueness of solution by using a mixed equilibrium formulation with suitable selected functions together with a fixed-point principle for history–dependent operators. Then, we apply the abstract result to show the unique weak solvability to a dynamic viscoelastic frictional contact problem. The contact law involves a unilateral Signorini-type condition for the normal velocity combined with the nonmonotone normal damped response condition while the friction condition is a version of the Coulomb law of dry friction in which the friction bound depends on the accumulated slip.

Intelligent Extraction and Generation Technology of Emergency Plan

<p>Natural disasters will bring a huge threat to the safety of human life and property. When disasters happen, leaders at all levels need to respond in time. Emergency plans can be regarded as the effective guidance of natural disaster emergency responses, and they include the textual descriptions of emergency response processes in terms of natural language. In this paper, we propose an approach to automatically extract emergency response process models from Chinese emergency plans, and can automatically generate appropriate emergency plans. First, the emergency plan is represented as a text tree according to its layout markups and sentence-sequential relations. Then, process model elements, including four-level response condition formulas, executive roles, response tasks, and flow relations, are identified by rule-based approaches. An emergency response process tree is generated from both the text tree and extracted process model elements, and is transformed to an emergency response process that is modeled as business process modeling notation. Finally, when different disasters occur, a new plan is generated according to the training of historical plan database. A large number of experiments in the actual emergency plan show that this method can extract the emergency response process model, and can generate a suitable new plan.</p>

A new class of hyperbolic variational–hemivariational inequalities driven by non-linear evolution equations

The aim of the paper is to introduce and investigate a dynamical system which consists of a variational–hemivariational inequality of hyperbolic type combined with a non-linear evolution equation. Such a dynamical system arises in studies of complicated contact problems in mechanics. Existence, uniqueness and regularity of a global solution to the system are established. The approach is based on a new semi-discrete approximation with an application of a surjectivity result for a pseudomonotone perturbation of a maximal monotone operator. A new dynamic viscoelastic frictional contact model with adhesion is studied as an application, in which the contact boundary condition is described by a generalised normal damped response condition with unilateral constraint and a multivalued frictional contact law.

Fast optimism, slow realism? Causal evidence for a two-step model of future thinking

Future optimism is a widespread phenomenon, often attributed to the psychology of intuition. However, causal evidence for this explanation is lacking, and sometimes cautious realism is found. One resolution is that thoughts about the future have two steps: A first step imagining the desired outcome, and then a sobering reflection on how to get there. Four pre-registered experiments supported this two-step model, showing that fast predictions are more optimistic than slow predictions. The total sample consisted of 2,116 participants from USA and Norway, providing 9,036 predictions. In Study 1, participants in the fast-response condition thought positive events were more likely to happen and that negative events were less likely, as compared to participants in the slow-response condition. Although the predictions were optimistically biased in both conditions, future optimism was significantly stronger among fast responders. Participants in the fast-response condition also relied more on intuitive heuristics (CRT). Studies 2 and 3 focused on future health problems (e.g., getting a heart attack or diabetes), in which participants in the fast-response condition thought they were at lower risk. Study 4 provided a direct replication, with the additional finding that fast predictions were more optimistic only for the self (vs. the average person). The results suggest that when people think about their personal future, the first response is optimistic, which only later may be followed by a second step of reflective realism. Current health, income, trait optimism, perceived control and happiness were negatively correlated with health-risk predictions, but did not moderate the fast-optimism effect.

Pitch and Duration Pattern Sequence Tests in 7- to 11-Year-Old Children: Results Depend on Response Mode

Pitch pattern sequence (PPS) and duration pattern sequence (DPS) tests are frequently used in the assessment of auditory processing disorder. Current recommendations suggest alternate, interchangeable modes for responding to stimuli.The objective of the study is to evaluate the influence of response mode (i.e., humming, pointing, and labeling) and age on PPS and DPS performance of 7- to 11-year-old children.Laboratory-based testing of school children. Cross-sectional comparison of age, with repeated measures of age, test, ear, and response mode.From 452 children recruited, 228 right-handed children (109 girls) aged 7 years to 11 years 11 months (mean age 9 years 4 months) completed at least one test (PPS: 211, DPS: 198), and 181 children completed both tests. Audiology inclusion criteria include normal hearing thresholds (≤15 dB HL at octave frequencies 250–8000 Hz); word recognition in quiet ≥92%; tympanogram peak compensated static acoustic compliance 0.4–1.6 mmhos; and tympanometric peak pressure −100 to +50 daPa, all in both ears. Other inclusion criteria were Portuguese as first language; right handed; no musical training; no related, known, or observed phonological, learning, neurologic, psychiatric, or behavioral disorder; otologic history; and delayed neuropsychomotor or language development.PPS: 30 trials per ear and response condition of three consecutive 500 msec duration intermixed high (1430 Hz) or low (880 Hz) frequency tones presented monaurally at 50 dB HL. The first response condition was humming followed by labeling (naming: high or low). DPS: As per PPS except 1000 Hz tones of intermixed 500 (long) and 250 msec (short) duration. First response was pointing (at a symbolic object) followed by labeling. Trends across age and between tests were assessed using repeated measures generalized linear mixed models. Correlation coefficients were calculated to assess relations among test scores. The two-sided significance level was 0.05.Older children performed better than younger children in all tasks. Humming the tone pattern (PPS humming) produced generally better performance than either articulating the attributes of the tones (labeling) or pointing to objects representing tone duration. PPS humming produced ceiling performance for many children of all ages. For both labeling tasks and DPS pointing, performance was better on the PPS than on the DPS, for stimulation of the right than the left ear, and in boys than girls. Individual performance on the two tasks was highly correlated.Response mode does matter in the PPS and DPS. Results from humming should not be combined with or be a substitute for results obtained from a labeling response. Tasks that rely on labeling a tonal stimulus should be avoided in testing hearing in children or other special populations.

Response of Macrobenthic Invertebrate to Organic Carbon and Particle Size in Lagos Lagoon, Nigeria

Macrobenthic fauna communities are important constituents of soft bottom marine ecosystems which inhabit the bottom environments playing a key factor in controlling structure and functioning of the aquatic environment. Lagos lagoon is the most exposed lagoon to anthropogenic influence in Nigeria coastal lagoon system. Bimonthly sampling was carried out in the Lagos lagoon from September 2014 - July 2016 for water and sediment in twenty – four stations to examine response condition of benthic communities to measures of water quality and sediment quality in Lagos lagoon in order to understand the benthic condition of the aquatic environment. A range of 9 – 91% for sand, 7 – 25% for silt, 0 – 73% for clay while a range of 0 – 4.77 was observed for TOC. The Diversity (H,) richness (d) and evenness (j) were positively correlated with the silt sediment particle size and. Kruskal-Wallis test showed that there was significant difference (p<0.05) between species richness and diversity at all sampling stations. Analysis of variance (ANOVA) showed no significant difference (p>0.05) in mean percentage particle sizes and TOC recorded at the stations but was significant (p<0.05) between TOC and macrobenthic invertebrates. The overall low diversity of macrobenthic fauna observed was attributed to anthropogenic activities majorly industrial dredging and local sand mining which altered the sediment characteristics of the aquatic ecosystem. Assessments of human induced stressors in the lagoon provided information useful for strict regulations and environmental policies to help prevent the aquatic environment from continuous deterioration hence, causing more loss of biodiversity. Responses of macrobenthic invertebrates to measured variables showed that there are high abundance and diversity of ecological groups of sensitive species majorly distributed around the slightly disturbed zones of the study area. In summary, variables examined in this study showed that the total organic content does not have a depleting effect on the abundance of macrobenthic invertebrates because the values are within permissible limits but the particle size characteristics present in this study showed good environmental indicator for evaluating macrobenthic invertebrate responses to stress pattern in water bodies along the coastal areas surrounded by various human activities.