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Hydrodynamic bearing is becoming an indispensable component of high-accuracy devices such as high-speed machine tools. Recently, the study of textured surface bearing has become one of the highly researched topics. Among the different types of surface texture, partially textured bearing shows outstanding performances on anti-vibration. However, most of the research focuses on the theoretical models of partial texture. In this paper, several bearings with no texture, full texture and partial texture are fabricated for stability and stiffness tests. The result shows that the partially textured bearings with 60% of textured ratio and 4.9% of area ratio exhibit the best properties, which could decrease the maximum amplitude by 45.8% at 9000 rpm. In addition, the textured surface with the optimal textured ratio of 60% can reduce the static stiffness and improve the dynamic stiffness. Therefore, partially textured bearings are particularly significant to the stability enhancement of the bearing system, which can lead to the performance and security improvement of the sliding bearing in high-speed applications.

We investigate the critical transitions in the ensemble of nonlinear oscillators interacting with the dynamical environment based on a threshold. The threshold is encoded by the amplitude of individual oscillators present in the network. The key idea is that whenever the oscillator’s amplitude is above the threshold, that node will be coupled to the environment with particular interaction strength. This consideration mimics the mechanism of quorum sensing by which many biological and chemical systems attain collective behavior when the population density reaches the threshold. We found the emergence of first-order discontinuous transition to steady states when the threshold is less than the maximum amplitude. We also deduced the general expression to obtain critical points in the chosen models.

The disadvantages of the separate use of gasoline and CNG pose great challenges to the development of spark ignition (SI) engines. One of the major obstacles to achieving higher thermal efficiency in gasoline engines is the knocking phenomenon. One solution to tackle this problem is the use of a combination of gasoline and CNG. Gasoline can be used as the predominant fuel due to having higher burning velocity. In the current study, different fuel mixtures containing 100%, 90%, 80%, and 70% gasoline and the rest NG (G100, G90, G80, and G70, respectively) were investigated in a single-cylinder SI research engine. The aim was to investigate the knocking features of the mixtures at the stoichiometric equivalence ratio, the compression ratio of 11, and the engine speed of 1800 rpm. After capturing data for each mixture at every spark advance and analyzing 400 subsequent cycles, the required processes were performed to determine the knocking features of the combinations at Optimum Spark Advances (OSA). At the OSA of G100, the average maximum amplitude of pressure oscillation $$(\overline{\text{MAPO}}_{\text{Tot}} )$$ and the knocking cycle percentage (%KC) were found to be 0.289 bar and 5.3%, respectively, and the distance between OSA and the impending knock limit advance (Δθ) was found to be less than 1 °CA. With the increase in NG proportion in the fuel mixture, $$\overline{\text{MAPO}}_{\text{Tot}}$$ and %KC decreased significantly, as their values in G80 reached 0.156 bar and 0.5%, respectively. Furthermore, as NG fraction increased, Δθ also increased significantly as its value reached 4.5 °CA in G70.

Transcutaneous electrical stimulation (TES) is a frequently used adjunctive modality in dysphagia rehabilitation. Stimulating deeper swallowing muscles requires higher TES amplitude. However, TES amplitude is limited by maximum amplitude tolerance (MAT). Previous studies have reported high interindividual variability regarding MAT and perceived discomfort. This variability might be one of the potential reasons of conflicting outcomes in TES-based swallowing studies. MAT and perceived discomfort are influenced by a variety of biopsychological factors. The influence of these factors related to swallow applications is poorly understood. This study explored the relation of biopsychological factors with MAT and perceived discomfort related to TES in the submental area. A convenience sample of thirty community-dwelling older adults between 60 and 70 years of age provided data for this study. Gender, submental adipose tissue thickness, perceptual pain sensitivity, and pain-coping strategies were evaluated for each subject. Subsequently, MAT and perceived discomfort level were determined using TES on the submental area. Relation of different biopsychological variables with MAT and discomfort level was examined using Pearson and Spearman correlation, and Mann–Whitney U test. Results indicated that neither gender nor adipose thickness was related to MAT and perceived discomfort. Among studied pain-coping strategies, catastrophizing was significantly related to MAT(r = – 0.552, p

Yoshida and Yamagishi (Ann. Geophys. 28, 417, 2010) found that the rate of decrease in the smoothed monthly mean sunspot number [ $R_{\mathrm{I}}$ ] over the final three years of a solar cycle or $R_{\mathrm{I}}$ itself at three years before the solar minimum [ $R_{ \mathrm{min}}$ ] can be used as a precursor for the ensuing maximum amplitude [ $R_{\mathrm{m}}$ ] if the time of $R_{\mathrm{min}}$ can be predicted in advance. The $R_{\mathrm{I}}$ series of the new version is employed to carefully analyze the decrease rate [ $\beta $ ] at different months [ $m$ ] before $R_{\mathrm{min}}$ and over different time intervals [ $\Delta m$ ] in this study. It is found that $R_{\mathrm{m}}(n)$ of Solar Cycle $n$ is best correlated ( $r=0.831$ ) with the preceding $\beta (n-1, m, \Delta m)$ over the final $\Delta m=m=39$ months. In addition, $R_{\mathrm{m}}$ is found to be best correlated ( $r=0.834$ ) with the $R_{\mathrm{I}}$ value 39 months before the preceding minimum. For the even- (odd-)numbered cycles, $R_{\mathrm{m}}$ is best correlated, $r=0.956$ (0.747), with the rate of decrease over $\Delta m= 38 (43)$ months interval from $m=39(47)$ months before the solar minimum, and $R_{\mathrm{m}}$ is best correlated, $r=0.964(0.739)$ , with the $R_{\mathrm{I}}$ -value 39 (46) months before the solar minimum. Based on this method and the inferred end time of Solar Cycle 24, the amplitude of Solar Cycle 25 is predicted to be $R_{\mathrm{m}}=130.0\pm 31.9$ , occurring around October 2024 $\pm 13$ (months).

Motivated by a successful prediction on the peak of solar cycle 24 (81.7, comparable to the observed 81.9, Du in Astrophys. Space Sci. 338:9, 2012), based on the logarithmic relationship between the maximum amplitude ( $R_{ \mathrm{m}}$ ) of a solar cycle and the preceding minimum $aa$ geomagnetic index ( $aa_{\mathrm{min}}$ ), we perform a prediction on the peak of the upcoming cycle 25 using the sunspot number of the new version instead. If the suggested error in $aa$ (3 nT) before 1957 is corrected, the correlation between $\ln R_{\mathrm{m}}$ and $\ln aa_{\mathrm{min}}$ ( $r=0.92$ ) is stronger than that not corrected ( $r=0.86$ ). Based on this relationship, the peak value of cycle 25 is predicted to be $R_{\mathrm{m}}(25)\simeq 151.1\pm 16.9$ , about 30% stronger than cycle 24. Employing the ‘Waldmeier effect’ that the rise time of a cycle is well anti-correlated to its amplitude, we estimated the rise time, $T_{\mathrm{a}}(25)=4.3\pm 0.2\pm 0.6$ , and the peak time of cycle 25, $2024.1 \pm 0.8 $ (years), which is during April 2023 and November 2024.

The Joint Australian Tsunami Warning Centre provides forecasts of tsunami arrival times based on the Tsunami Travel Times (TTT) software. In this work, travel times from a pre-computed scenario database and TTT are evaluated through comparison with observed arrival times at tide gauges and tsunameters. It is found that travel times from the scenario database are at least as accurate as those from TTT and in most cases, more accurate. The ‘best’ scenario-based method is Tp20—the time of arrival of the first peak that is at least 20% of the maximum amplitude at that point.

The forced vibrations of a mechanical vibration isolation system consisting of a ball vibration absorber (BVA) with linear viscous resistance and a movable carrier body under an external harmonic load are considered. Appell’s formalism is used to formulate and numerically solve the equations of combined motion of the heavy ball without sliding in the spherical cavity of the carrier body. The frequency response of the system and curves of the maximum amplitude of vibrations of the carrier body versus the radius of the spherical cavity and the coefficient of viscous resistance of the BVA are plotted. The conditions and constraints on the rolling of the heavy ball in the spherical cavity without sliding are established.

This study investigates the seasonally meridional shifts of the subarctic frontal zone (SAFZ) and its relationship with North Pacific storm track (NPST). It is found that the SAFZ is at its southernmost in winter but northernmost in summer, and the maximum standard deviations of the SAFZ meridional position is between 153° E and 163° E, with the maximum amplitude of about 2.5 latitudes. When the SAFZ shifts northward (southward), the NPST moves poleward (equatorward) with the distinct seasonally anomalous patterns, i.e., the NPST meridional displacement is larger in winter and autumn, followed by that in spring, and it is smallest in summer. It is also revealed that the near-surface baroclinicity and baroclinic energy conversion (BCEC) may be responsible for the seasonal variations of the relationship between the NPST and the SAFZ shifts. Accompanied by the northward (southward) shift of the SAFZ, the near-surface baroclinicity zone moves northward (southward) significantly, and more mean available potential energy converts to eddy available potential energy and further transferred to eddy kinetic energy in the northern (southern) part of the NPST, resulting in more pronounced northward (southward) movement of the NPST in winter and autumn. However, the NPST anomalous patterns are relatively weak when the near-surface baroclinicity and BCEC anomalies are small in spring and summer.

An Mw 8.2 earthquake and tsunami occurred off- shore the Pacific coast of Me´xico on 2017-09-08, at 04:49 UTC. Costa Rican tide gauges have registered a total of 21 local, regional and far-field tsunamis. The Quepos gauge registered 12 tsunamis between 1960 and 2014 before it was relocated inside a harbor by late 2014, where it registered two more tsunamis. This paper analyzes the 2017 Me´xico tsunami as recorded by the Quepos gauge. It took 2 h for the tsunami to arrive to Quepos, with a first peak height of 9.35 cm and a maximum amplitude of 18.8 cm occurring about 6 h later. As a decision support tool, this tsunami was modeled for Quepos in real time using ComMIT (Community Model Interface for Tsunami) with the finer grid having a resolu- tion of 1 arcsec (* 30 m). However, the model did not replicate the tsunami record well, probably due to the lack of a finer and more accurate bathymetry. In 2014, the National Tsunami Moni- toring System of Costa Rica (SINAMOT) was created, acting as a national tsunami warning center. The occurrence of the 2017 Me´xico tsunami raised concerns about warning dissemination mechanisms for most coastal communities in Costa Rica, due to its short travel time. SINAMOT

Tremor is a rhythmic, involuntary, oscillatory movement of a limb produced by alternating contractions of reciprocally innervated muscles. More than 4% of the population over 40 years old suffer from tremor. There is no cure for most tremors, and while psychological therapy is sometimes helpful, tremors are usually treated with either medication or invasive surgery including thalamotomy and deep brain stimulation. Both medications and surgery may have adverse effects, and thus, there is a growing interest in developing non-invasive vibration attenuation devices. This paper presents a passive absorber device for attenuating pronation/supination tremor, dubbed Vib-bracelet. It is based on the principles of dynamic vibration absorption and is tuned to the frequency of the tremor. Prototypes were manufactured and tested on a mechanical model of the human forearm. Simulations and experiments demonstrate the efficiency of the device in attenuating vibrations in the range of 4-6 Hz, which is the range of frequency of observed tremor, with maximum amplitude attenuation of 85%.

Surface waviness models utilized to describe the excitation events in the ball bearings (BABs) play an important role in predicting the vibrations of the ball bearing systems. This work proposes a comparative study on the most relevant existing surface waviness models. One model is named as time-varying displacement (TVD) model, which can only describe the time-varying displacement excitation (TDIE). Another model is named as TVDS model, which can describe the TDIE and time-varying contact stiffness coefficient excitation (TCSE). The influences of the wave number, maximum amplitude, nonuniform distribution on the contact stiffness coefficients are studied, as well as vibrations of the BAB. The comparative results demonstrate that the time-varying displacement and stiffness (TVDS) model can provide a more accurate impulses caused by the uniform and nonuniform surface waviness on the races of the BABs. It also seems that the surface waviness distribution has a significantly influence on vibrations of the BABs.

The National Oceanic and Atmospheric Administration (NOAA) National Centers for Environmental Information (NCEI) and co-located World Data Service for Geophysics maintain the global tsunami archive consisting of the historical tsunami database, imagery, and raw and processed water level data. The historical tsunami database incorporates, where available, maximum wave heights for each coastal tide gauge and deep-ocean buoy that recorded a tsunami signal. These data are important because they are used for tsunami hazard assessment, model calibration, validation, and forecast and warning. There have been ongoing discussions in the tsunami community about the correct way to measure and report these wave heights. It is important to understand how these measurements might vary depending on how the data were processed and the definition of maximum wave height. On September 16, 2015, an 8.3 M w earthquake located 48 km west of Illapel, Chile generated a tsunami that was observed all over the Pacific region. We processed the time-series water level data for 57 coastal tide gauges that recorded this tsunami and compared the maximum wave heights determined from different definitions. We also compared the maximum wave heights from the NCEI-processed data with the heights reported by the NOAA Tsunami Warning Centers. We found that in the near field different methods of determining the maximum tsunami wave heights could result in large differences due to possible instrumental clipping. We also found that the maximum peak is usually larger than the maximum amplitude (½ peak-to-trough), but the differences for the majority of the stations were

The variability of subsurface currents in the equatorial Indian Ocean is studied using high resolution Ocean General Circulation Model (OGCM) simulations during 1958–2009. February–March eastward equatorial subsurface current (ESC) shows weak variability whereas strong variability is observed in northern summer and fall ESC. An eastward subsurface current with maximum amplitude in the pycnocline is prominent right from summer to winter during strong Indian Ocean Dipole (IOD) years when air-sea coupling is significant. On the other hand during weak IOD years, both the air-sea coupling and the ESC are weak. This strongly suggests the role of ESC on the strength of IOD. The extension of the ESC to the summer months during the strong IOD years strengthens the oceanic response and supports intensification and maintenance of IODs through modulation of air sea coupling. Although the ESC is triggered by equatorial winds, the coupled air-sea interaction associated with IODs strengthens the ESC to persist for several seasons thereby establishing a positive feedback cycle with the surface. This suggests that the ESC plays a significant role in the coupled processes associated with the evolution and intensification of IOD events by cooling the eastern basin and strengthening thermocline-SST (sea surface temperature) interaction. As the impact of IOD events on Indian summer monsoon is significant only during strong IOD years, understanding and monitoring the evolution of ESC during these years is important for summer monsoon forecasting purposes. There is a westward phase propagation of anomalous subsurface currents which persists for a year during strong IOD years, whereas such persistence or phase propagation is not seen during weak IOD years, supporting the close association between ESC and strength of air sea coupling during strong IOD years. In this study we report the processes which strengthen the IOD events and the air sea coupling associated with IOD. It also unravels the connection between equatorial Indian Ocean circulation and evolution and strengthening of IOD.

We applied the Hilbert–Huang transform (HHT) method to extract the infrasound generated by the 2013 Lushan earthquake and its following aftershocks in China from a nearly continuous infrasound recode made 130 km from the earthquake epicenter. An improved STA/LTA algorithm was adopted for detecting the ambient infrasonic events from the data record. A powerful processing technique for non-stationary signal, the HHT, was applied to extract the significant intrinsic mode functions (IMFs) of the infrasonic signal associated with the earthquakes. The features of the extracted IMFs, such as the dominant frequency, the maximum amplitude and the spectral entropy, were investigated using Hilbert spectral analysis. Regression analysis between the maximum amplitude in the infrasound spectra and the magnitudes of the earthquakes was carried out to verify the source of the infrasound events detected. The results demonstrated that the HHT method could successfully identify the infrasound related to the earthquakes.

No study has investigated the alterations in the flexibility of beginners using an experimental protocol with basic techniques of Capoeira. To analyze the effects of 8 weeks of Capoeira progressive training program on the flexibility of beginners. Twenty-one individuals divided in two groups (Capoeira: n = 13; 26.1 ± 7.2 years; 22.7 ± 2.7 kg m2(−1) and control: n = 08; 27.1 ± 0.5 years; 24.3 ± 3.3 kg m2(−1)) participated in the study. The Capoeira group performed 8 weeks of Capoeira progressive training program (two sessions per week lasting 60 min each). The experimental protocol used was exclusively based on the basic techniques of a programmed Capoeira training system. Before and after the intervention, measurements were performed aiming to analyze (1) trunk flexion flexibility through a sit-and-reach test using a Wells’ Bench (WBtf), (2) passive tension (PThf), and (3) maximum amplitude of hip flexion (MAhf) through goniometry. A two-way ANOVA revealed a main effect of group by time interaction to PThf (F = 11.797; P = 0.003; η p 2 = 0.383) and MAhf (F = 9.650; P = 0.006; η p 2 = 0.337). No significant main effect of group by time interaction occurred to WBtf (F = 3.320; P = 0.084; η p 2 = 0.149). The relative changes (∆ %) before and after the intervention in both groups showed that the Capoeira group significantly differed to the control group in the PThf (Capoeira: 46.2 ± 29.9 % vs. control: 5.7 ± 27.6 %; P = 0.003) and MAhf (Capoeira: 22.4 ± 24.5 % vs. control: −6.1 ± 13.1 %; P = 0.006). Eight weeks of Capoeira progressive training program resulted in a significant improvement in angular flexibility for beginners.

An increasing number of treatments for spinal cord injury (SCI) out of the laboratories and in clinical trials pass. Many of them are used as soon as possible after the injury with the hope of weakening the secondary damage and maximize the preservation of nerve tissue. The aim of the study was to evaluate the effects metilprednizalonium and motor training at an experimental spinal cord injury in rats. To investigate the status of the peripheral neuromuscular system registered motor response (M-response) muscles. In the early period after spinal cord injury was observed, a decrease of the maximum amplitude of M-response. With that, in the group of animals with the introduction of metilprednizalonium, amplitude of M-response was higher than that without drug therapy. Combined therapy metilprednizalonium and motor training has a positive effect on the recovery of motor function in chronic period after contusion spinal cord injury in rats.

Steady-state dynamics of linear, Euler–Bernoulli beams under harmonic excitation coupled to a nonlinear energy sink (NES) with nonlinear stiffness of order three is considered. By applying complex-averaging and arc-length continuation methods, semi-analytical approximation for the response of the coupled system is obtained. Analysis is based on 1:1 resonance condition. To compare with the performance of NES, a linear tuned mass damper (TMD) is designed. The results show that the performance of NES is dependent on designed force amplitude. For lower amplitude, NES has a better performance than TMD, but for force amplitude greater than this designed force, TMD has a better performance. In order to have better performance for NES compared with TMD, NES must be designed for the maximum amplitude of the exciting force.

The consideration of soil nonlinearity is important for the accurate estimation of the site response. To evaluate the soil nonlinearity during the 2008 Ms8.0 Wenchuan Earthquake, 33 strong-motion records obtained from the main shock and 890 records from 157 aftershocks were collected for this study. The horizontal-to-vertical spectral ratio (HVSR) method was used to calculate five parameters: the ratio of predominant frequency (RFp), degree of nonlinearity (DNL), absolute degree of nonlinearity (ADNL), frequency of nonlinearity (fNL), and percentage of nonlinearity (PNL). The purpose of this study was to evaluate the soil nonlinearity level of 33 strong-motion stations and to investigate the characteristics, performance, and effective usage of these five parameters. Their correlations with the peak ground acceleration (PGA), peak ground velocity (PGV), average uppermost 30-m shear-wave velocity (V S30), and maximum amplitude of HVSR (A max) were investigated. The results showed that all five parameters correlate well with PGA and PGV. The DNL, ADNL, and PNL also show a good correlation with A max, which means that the degree of soil nonlinearity not only depends on the ground-motion amplitude (e.g., PGA and PGV) but also on the site condition. The fNL correlates with PGA and PGV but shows no correlation with either A max or V S30, implying that the frequency width affected by the soil nonlinearity predominantly depends on the ground-motion amplitude rather than the site condition. At 16 of the 33 stations analyzed in this study, the site response showed evident (i.e., strong and medium) nonlinearity during the main shock of the Wenchuan Earthquake, where the ground-motion level was almost beyond the threshold of PGA > 200 cm/s2 or PGV > 15 cm/s. The site response showed weak and no nonlinearity at the other 14 and 3 stations. These results also confirm that RFp, DNL, ADNL, and PNL are effective in identifying the soil nonlinearity behavior. The identification results vary for different parameters because each parameter has individual features. The performance of the PNL was better than that of DNL and ADNL in this case study. The thresholds of ADNL and PNL are proposed to be 2.0 and 7%, respectively.

The scale-eating cichlid Perissodus microlepis exhibits significant lateralised predation behaviour using an asymmetric mouth. But how the acquisition of the behavioural laterality depends, if at all, on experience during development remains obscure. Here, naïve juveniles were tested in a series of predation sessions. Initially, they attacked both sides of the prey, but during subsequent sessions, attack direction gradually lateralised to the skewed mouth (dominant) side. Attack side preference of juveniles that had accumulated scale-eating experience during successive sessions was significantly higher than that of naïve juveniles at the same age and naïve adults. Thus, the lateralised behaviour was a learned experience, and did not develop with age. Surprisingly, however, both maximum amplitude and angular velocity of body flexion during attack of naïve fish was dominant on one side. Therefore, scale-eating fish have a naturally stronger side for attacking prey fish, and they learn to use the dominant side through experience.

Background The inserted cochlear implanted electrode is covered at the site of the round window or cochleostomy to prevent infections and leakage. In a surgically hearing preservational concept, low intracochlear pressure changes are of high importance. The aim of this study was to observe intracochlear pressure changes due to different sealing techniques in a cochlear model. Methods Cochlear implant electrode insertions were performed in an artifical cochlear model and the intracochlear pressure changes were recorded in parallel with a micro-pressure sensor positioned in the apical region of the cochlea model to follow the maximum amplitude of intracochlear pressure. Four different sealing conditions were compared: 1) overlay, 2) overlay with fascia pushed in, 3) donut-like fascia ring, 4) donut-like fascia ring pushed in. Results We found statistically significant differences in the occurrence of maximum amplitude of intracochlear pressure peak changes related to sealing procedure comparing the different techniques. While the lowest amplitude changes could be observed for the overlay technique (0.14 mmHg ± 0.06) the highest values could be observed for the donut-like pushed in technique (1.79 mmHg ± 0.69). Conclusion Sealing the electrode inserted cochlea can lead to significant intracochlear pressure changes. Pushing in of the sealing tissue cannot be recommended.

Rayleigh waves significantly compromise the safety of tunnel portals. This paper establishes a three-dimensional numerical model, with a plastic-damage model for the concrete lining structure, to analyze the damage evolution of the tunnel portal during the longitudinal propagation of Rayleigh waves. To generate the wave field, a Rayleigh wave input method based on viscous-spring artificial boundary is developed. The submodeling technique is employed to overcome difficulties introduced by contradictions between element size, model scale and affordable computational cost. The simulation results, including the deformation of pavement at the entrance and the crack pattern of the tunnel lining, correspond well with the field observation of the Longxi Tunnel during the Wenchuan Earthquake. This paper proposes that the opening width of predominant circumferential cracks and a dimensionless damage index based on the internal damage variable can be used to quantitatively estimate the damage extent of the lining structure. The result of damage assessment shows that all damage is limited within a certain scope of the tunnel portal and that the extent of each crack decreases with its increasing distance from the entrance. The extent of damage may also be induced through earthquake loading with a relatively lower amplitude. Therefore, the cyclic and accumulative effect of successive earthquake loading over time, rather than simply, the effect of loading with a maximum amplitude, can determine the final damage state of lining structure. Although incapable of preventing the appearance of hairline cracks, the strengthening effect of reinforcement remarkably reduces the maximum width of crack openings and the overall damage extent of the lining structure. Moreover, the presence of reinforcing steels prevents micro-cracks from expanding to wider crack, which is essential to keep the tunnel lining waterproof and mechanically stabilized. The simulation methodology introduced in this paper could also potentially reliably predict the damage process of the tunnel lining and the extent of damage under the effect of complicated earthquake loading, aside from the Rayleigh wave.

Recently, methods for adding emotion to synthetic speech have received considerable attention in the field of speech synthesis research. We previously proposed a case-based method for generating emotional synthetic speech by exploiting the characteristics of the maximum amplitude and the utterance time of vowels, and the fundamental frequency of emotional speech. In the present study, we propose a method in which our reported method is further improved by controlling the fundamental frequency of emotional synthetic speech. As an initial investigation, we adopted the utterance of a Japanese name that is semantically neutral. By using the proposed method, emotional synthetic speech made from the emotional speech of one male subject was discriminable with a mean accuracy of 83.9 % when 18 subjects listened to the emotional synthetic utterances of "angry," "happy," "neutral," "sad," or "surprised" when the utterance was the Japanese name "Taro," or "Hiroko." Further adjustment of fundamental frequency in the proposed method made a much clearer impression on the subjects for emotional synthetic speech.

All available tsunami observations at tide gauges situated along the North American coast were examined to determine if there is any clear relationship between maximum amplitude and signal duration. In total, 89 historical tsunami recordings generated by 13 major earthquakes between 1952 and 2011 were investigated. Tidal variations were filtered out of the signal and the duration between the arrival time and the time at which the signals drops and stays below 0.3 m amplitude was computed. The processed tsunami time series were evaluated and a linear least-squares fit with a 95 % confidence interval was examined to compare tsunami durations with maximum tsunami amplitude in the study region. The confidence interval is roughly 20 h over the range of maximum tsunami amplitudes in which we are interested. This relatively large confidence interval likely results from variations in local resonance effects, late-arriving reflections, and other effects.

With the help of the similarity transformation connected the variable-coefficient nonlinear Schrodinger equation with the standard nonlinear Schrodinger equation, we firstly obtain first-order and second-order rogue wave solutions in two dimensional graded-index waveguides. Then, we investigate the nonlinear tunneling of controllable rogue waves when they pass through nonlinear barrier and nonlinear well. Our results indicate that the propagation behaviors of rogue waves, such as postpone, sustainment and restraint, can be manipulated by choosing the relation between the maximum value of the effective propagation distance Z m and the effective propagation distance corresponding to maximum amplitude of rogue waves Z 0. Postponed, sustained and restrained rogue waves can tunnel through the nonlinear barrier or well with increasing, unchanged and decreasing amplitudes by modulating the ratio of the amplitudes of rogue waves to barrier or well height.

In recent years, a large number of quarry blasts have been detonated in the eastern Black Sea region. When these blasts are recorded by seismic stations, they contaminate the regional earthquake catalog. It is necessary to discriminate quarry blast records from the earthquake catalogs in order to determine the real seismicity of the region. Earthquakes and quarry blasts can be separated through different methods. These methods should be applied concurrently in order to safely distinguish these events. In this study, we discriminated quarry blasts from earthquakes in the eastern Black Sea region of Turkey. We used 186 seismic events recorded by the Karadeniz Technical University and Bogazici University Kandilli Observatory Earthquake Research Institute stations which are Trabzon, Espiye, Pazar, Borcka, Aydintepe, and Gumushane between years of 2002 and 2010. For the discrimination of quarry blasts from earthquakes, we used both, statistical methods (calculation of the maximum ratio of S to P waves (S/P), complexity (C)) and spectral methods (spectrogram calculation). These methods included measuring the maximum amplitude S/P, C, spectral ratio, and time-frequency analysis. We especially relied on two-dimensional time-frequency analysis methods to discriminate quarry blasts from earthquakes in Turkey. As a result of this study, 68 % of the examined seismic events were determined to be quarry blasts and 32 % to be earthquakes. The earthquakes occurring on land are related to small faults and the blasts are concentrated in large quarries. Nearly 40 % of the earthquakes occurred in the Black Sea, most of them are related to the Black Sea thrust belt, where the largest earthquake was observed in the time period studied. The areas with the largest earthquake potential in the eastern Black Sea region are in the sea.

The coast of California was significantly impacted by two recent teletsunami events, one originating off the coast of Chile on February 27, 2010 and the other off Japan on March 11, 2011. These tsunamis caused extensive inundation and damage along the coast of their respective source regions. For the 2010 tsunami, the NOAA West Coast/Alaska Tsunami Warning Center issued a state-wide Tsunami Advisory based on forecasted tsunami amplitudes ranging from 0.18 to 1.43 m with the highest amplitudes predicted for central and southern California. For the 2011 tsunami, a Tsunami Warning was issued north of Point Conception and a Tsunami Advisory south of that location, with forecasted amplitudes ranging from 0.3 to 2.5 m, the highest expected for Crescent City. Because both teletsunamis arrived during low tide, the potential for significant inundation of dry land was greatly reduced during both events. However, both events created rapid water-level fluctuations and strong currents within harbors and along beaches, causing extensive damage in a number of harbors and challenging emergency managers in coastal jurisdictions. Field personnel were deployed prior to each tsunami to observe and measure physical effects at the coast. Post-event survey teams and questionnaires were used to gather information from both a physical effects and emergency response perspective. During the 2010 tsunami, a maximum tsunami amplitude of 1.2 m was observed at Pismo Beach, and over $3-million worth of damage to boats and docks occurred in nearly a dozen harbors, most significantly in Santa Cruz, Ventura, Mission Bay, and northern Shelter Island in San Diego Bay. During the 2011 tsunami, the maximum amplitude was measured at 2.47 m in Crescent City Harbor with over $50-million in damage to two dozen harbors. Those most significantly affected were Crescent City, Noyo River, Santa Cruz, Moss Landing, and southern Shelter Island. During both events, people on docks and near the ocean became at risk to injury with one fatality occurring during the 2011 tsunami at the mouth of the Klamath River. Evaluations of maximum forecasted tsunami amplitudes indicate that the average percent error was 38 and 28 % for the 2010 and 2011 events, respectively. Due to these recent events, the California tsunami program is developing products that will help: (1) the maritime community better understand tsunami hazards within their harbors, as well as if and where boats should go offshore to be safe, and (2) emergency managers develop evacuation plans for relatively small “Warning” level events where extensive evacuation is not required. Because tsunami-induced currents were responsible for most of the damage in these two events, modeled current velocity estimates should be incorporated into future forecast products from the warning centers.

Many past studies have verified numerical simulations of tsunamis using only qualitative and subjective methods. This paper investigates the relative merits of several indices that can be used to objectively verify tsunami model performance. A number of commonly used indices, such as error in the maximum amplitude and root-mean-square error, are considered, as well as some further indices that have been developed for other specific applications. Desirable qualities of the indices are presented and these include computational efficiency, invariance when applied to tsunamis of any size or to time series of varying length (including relatively short series), and the ability to clearly identify a single best prediction from within a set of simulations. A scenario from the T2 tsunami scenario database is chosen as the control. From this, time series of sea-level elevations are extracted at designated test points located at a range of distances from the tsunami source region. Parameters of the T2 database are perturbed in order to examine the performance of the indices. Of the indices examined, several performed better than others, with Wilmott’s Index of Agreement and Watterson’s transformed Mielke index found to be the best. Combining data from multiple locations was shown to improve the performance of the indices. This study forms the basis for future evaluation of the indices using real observations of tsunamis.

We consider the propagation of ultrashort optical pulses in a thin film of a topological insulator within the framework of an effective long-wave Hamiltonian for low-temperature media. The electromagnetic field is taken as classical Maxwellian. We reveal the dependence on the maximum amplitude of ultrashort optical pulses.

Based on the z-coordinate ocean model HAMSOM, we introduced the internal-tide viscosity term and applied the model to numerically investigate the M2 internal tide generation and propagation in the Luzon Strait (LS). The results show that (1) in the upper 250 m depth, at the thermocline, the maximum amplitude of the generated internal tides in the LS can reach 40 m; (2) the major internal tides are generated to the northwest of Itbayat Island, the southwest of Batan Island and the northwest of the Babuyan Islands; (3) during the propagation the baroclinic energy scattering and reflection is obvious, which exists under the effect of the specific topography in the South China Sea (SCS); (4) the westward-propagating internal tides are divided into two branches entering the SCS. While passing through 118°E, the major branch is divided into two branches again. The strongest internal tides in the LS are generated to the northwest of Itbayat Island and propagate northeastward to the Pacific. However, to the east of 122°E, most of the internal tides propagate southeastward to the Pacific as a beam.

The stresses developed in a body due to a moving load causing fracture are an interesting problem of mechanics having its application toward the stability of a medium. This paper is concerned with the stresses developed in an irregular isotropic half-space due to a normal moving load at a rough free surface. The irregularity has been taken in the form of a parabola and a rectangular irregularity has also been discussed as a special case of parabolic irregularity. Closed-form expressions for the normal and shear stresses have been obtained. The effect of friction, irregularity factor, and maximum amplitude of irregularity has been discussed for both stresses.

Using historical records on first and last frost and snow, spring cultivation, David peach blossom, autumn crop harvest, grade of sea freeze and change in northern citrus boundary, we reconstructed temperature change during 601–920 AD. The mean temperature of the winter half-year (October to April) over Central East China during this period was about −0.22°C higher than that of the present (1961–2000 AD mean). During 601–820 AD, mean temperature was about −0.52°C higher than the present. During 821–920 AD, the mean temperature was 0.42°C lower than the present. The temperature fluctuations were characterized by a maximum amplitude of 1.05°C at the centennial scale, 1.38°C at the 50–year scale, 2.02°C at the 30-year scale, and 2.3°C at the 20-year scale. There were four peaks warmer than today (601–620 AD, mean of 1°C higher temperature; 641–660 AD, 1.44°C; 701–720 AD, 0.88°C; 781–800 AD, 0.65°C). Three cold periods were in 741–760, 821–840, and 881–900 AD, the mean temperature of which was 0.37–0.87°C lower than the present.

A higher correlation tends to yield a more accurate prediction, so that a correlation as high as possible has been searched for and employed in the prediction of solar activity. Instead of using geomagnetic activity during the descending phase of the solar cycle, the minimum annual aa index (aa min) is used as an indicator for the ensuing maximum amplitude (R m) of the sunspot cycle. A four-cycle periodicity is roughly shown in the correlation between R m and aa min. The widely accepted Ohl’s precursor prediction method often fails due to the prediction error relative to its estimated uncertainty. An accurate prediction depends on the positive variation of the correlation rather than a higher correlation. Previous experiences by using this method indicate that a prediction for the next cycle, R m(24) = 80 ± 17, is likely to fail, implying that the sunspot maximum of Cycle 24 may be either smaller than 63 or greater than 97.

High-frequency oscillatory ventilation (HFOV) is thought to protect the lungs of acute respiratory distress syndrome (ARDS) patients. The performance and mechanical characteristics of high-frequency oscillatory ventilators, especially with regard to delivering appropriate tidal volume (V T) to compromised lungs, might affect the outcome of patients. We evaluated the performance of two such ventilators using a model lung with a position sensor. We tested the Metran R100 and SensorMedics 3100B. V T was measured using the model lung with the compliance set at 20 or 50 ml/cmH2O and the resistance at 0 or 20 cmH2O/l/s. Oscillator frequency was set at 5, 7, and 9 Hz, and amplitude was set at 25%, 50%, 75%, and 100% (100% being maximum amplitude available at each setting configuration). At each model lung setting, R100 delivered greater V T at 5 Hz. V T differences between the ventilators decreased as frequency increased and were negligible at 9 Hz. At each model lung setting and frequency, as amplitude increased from 25% to 100%, V T increased proportionally more with R100. With an I:E ratio of 1:1, 3100B delivered greater V T than with 1:2. Because it is able to deliver comparably greater V T, R100 may be a better choice for HFOV in critical ARDS patients. Better proportionality may be a result of more effective amplitude titration for adjusting PaCO2 during oscillation.

Neural networks have been widely used for many applications. One of the applications is forecasting. Many studies have proven that neural networks can provide good accuracy on forecasting future data with over than 80% accuracy. In this study, neural network is used to predict bearing defects. Two learning tasks, function approximation and pattern recognition, were used for detection and monitoring of defects in ball bearing. Given five categories of bearing defect, the neural networks have successfully proven the ability to distinguish one defect over the other with high accuracy. Acoustic emission (AE) was used as a measurement in this study. AE is defined as transient waves generated from a rapid release of strain energy by deformation or damage or on the surface of a material (1–3). The AE waves can provide information about bearing condition. Maximum amplitude and AE counts were used as the basis for detection.

Precursor techniques, in particular those using geomagnetic indices, often are used in the prediction of the maximum amplitude for a sunspot cycle. Here, the year 2008 is taken as being the sunspot minimum year for cycle 24. Based on the average aa index value for the year of the sunspot minimum and the preceding four years, we estimate the expected annual maximum amplitude for cycle 24 to be about 92.8±19.6 (1-sigma accuracy), indicating a somewhat weaker cycle 24 as compared to cycles 21 – 23. Presuming a smoothed monthly mean sunspot number minimum in August 2008, a smoothed monthly mean sunspot number maximum is expected about October 2012±4 months (1-sigma accuracy).

If the rise time RT, fall time FT, and total time TT (i.e., RT+FT) of a solar cycle are compared against the maximum amplitude Rz(max ) for the following cycle, then only the association between TT and Rz(max ) is inferred to be well anticorrelated, inferring that the larger (smaller) the value of Rz(max ) for the following cycle, the shorter (longer) the TT of the preceding cycle. Although the inferred correlation (−0.68) is statistically significant, the inferred standard error of estimate is quite large, so predictions using the inferred correlation are not very precise. Removal of cycle pairs 15/16, 19/20, and 20/21 (statistical outliers) yields a regression that is highly statistically significant (−0.85) and reduces the standard error of estimate by 18%. On the basis of the adjusted regression and presuming TT=140 months for cycle 23, the present ongoing cycle, cycle 24’s 90% prediction interval for Rz(max ) is estimated to be about 94±44, inferring only a 5% probability that its Rz(max ) will be larger than about 140, unless of course cycle pair 23/24 is a statistical outlier.

We measured temporal and spatial components of the waving display in a Uca tangeri population to look for inter-individual differences in male waving structure that may convey information about individual identity. We found evidence that the spatial components of wave structure, especially “Maximum amplitude” are responsible for most of the between-male variation of the display. This variation could reflect differences in individuals’ condition and/or could be used by conspecifics to discriminate amongst familiar and unfamiliar individuals.

Vertical coseismic deformation on non-causative fault caused by remote strong earthquakes (epicentral distance ≥1 500 km, M S≥7.0) are observed by fault-monitoring instruments of new type during recent two years. The monitoring result shows, delay time, maximum amplitude and duration of vertical deformation on the non-causative fault have remarkable close relationship with earthquakes magnitude and epicentral distance. The delay time of vertical coseismic deformation have positive linear relationship with epicentral distance. The velocity of coseismic deformation is 5.5 km/s, close to the velocity of surface wave in granite. The logarithms of maximum amplitude of coseismic deformation and epicentral distance have remarkable linear relationship with magnitude. The greater the magnitude and the closer the epicentral distance are, the bigger the maximum amplitude of coseismic deformation on non-causative fault will be. Relative to the epicentral distance, the magnitude is the most important factor to the duration of coseismic vertical deformation on the non-causative fault. Stronger earthquake causes longer vibration duration of coseismic deformation. The experiential equation of co-seismic deformation faults obtained by this work is significant on the coseismic deformation research.

As a precursor for predicting the maximum amplitude of the coming solar cycle, the skewness of the previous cycle proposed by Ramaswamy (1977) is revisited. The reliability of the prediction method is improved by separating odd and even cycles. A first method is proposed on the basis of calculated skewness. In that case, the prediction is available at the end of the previous cycle. A possibility to anticipate the availability of the skewness by about one year is pointed out. A second method, adding prediction of the skewness itself is studied. The statistical reliability is lower than in the first case, but the prediction of a cycle maximum is available at the maximum of the previous cycle.

The Great Tsunami of 26 December 2004 is described using data from seven tide gauges in India and others from surrounding areas in the Indian Ocean. The tsunami struck the Indian east coast around 0330 UTC. The amplitude was 2 m above the tide at Chennai, Paradip, and Colombo. The east coast of India (and of Sri Lanka) was hit shortly after high tide; Tuticorin and Colombo, however, were hit shortly after low tide. The tsunami wave propagated northward along the Indian west coast. All these gauges are to the west of the earthquake zone and the detided sea levels show first a rise in sea level with the arrival of the tsunami, and then a sharp decrease. Spectral and wavelet analysis of the detided series show that the maximum amplitude was at a period of 35–45 minutes, with another maximum around 20 minutes. Along the Indian east coast, however, there is another broad peak between 1–2 hours within the first few hours after the first tsunami wave.

Using a voltage-clamp technique in the whole-cell configuration, we studied voltage-operated calcium currents in retinal ganglion cells (RGCs) obtained from the rat eye. In all examined cells, we recorded high-threshold calcium currents with the mean maximum amplitude 285 ± 33 pA (104-593 pA; n = 22) at the membrane potential –10 to 0 mV. In a considerable part of the neurons (10 of 22; 45%), we also observed low-threshold calcium currents (published data on the presence of such currents in mammalian RGCs are contradictory). The mean maximum amplitude of the latter (low-threshold) currents was 99 ± 11 pA (54-157 pA; n = 10) at the membrane potential –35 mV. The observed differences in the patterns of voltage-dependent calcium currents in various RGCs can be related to functional differentiation of these cells.

The aim of the study was to detect patterns of spatial-current distribution in the late QRS and early ST-segments that distinguish Brugada-syndrome cases from complete right-bundle branch block (CRBBB). Magnetocardiograms (MCGs) were recorded from Brugada-syndrome patients (n = 6), CRBBB patients (n = 4) and the members of a control group (n = 33). The current distributions at six time points from Q-onset were estimated by producing current-arrow maps (CAMs). The angle of the current arrow of maximum amplitude at each time point was calculated. In the Brugada cases, the characteristic ST elevation was seen above the upper right chest, and abnormal currents appeared to be present in the right-ventricular outflow tract (RVOT). The angles of the abnormal arrows were -78 degrees +/- 51 degrees at 100 ms and -50 degrees +/- 61 degrees at 110 ms. In the cases of CRBBB, wide S- and R-waves were recorded above the upper right and lower right chest, respectively. The angles of the abnormal arrows for CRBBB were 152 degrees +/- 19 degrees at 100 ms, 159 degrees +/- 20 degrees at 110 ms, and 157 degrees +/- 19 degrees at 120 ms. The findings suggest that an abnormal current from the RVOT to the upper left chest may be a feature of the Brugada syndrome, and that the direction of this current is completely different from that seen in CRBBB.

In the quest for deciphering the neural code, theoretical advances were made which allow for the determination of the information rate inherent in the spike trains of nerve cells. However, up to now, the dependence of the information rate on stimulus parameters has not been studied in any neuron in a systematic way. Here, I investigate the information carried by the spike trains of H1, a motion-sensitive visual interneuron of the blowfly (Calliphora vicina) using a moving grating as a stimulus. Stimulus parameters fall in two classes: those that have only a minor effect on the information rate like increasing the frequency bandwidth or the maximum amplitude of the stimulus velocity, and those which dramatically affect the neural information rate, like varying the spatial size or the contrast of the visual pattern being moved. It appears that, for a broad range of complex stimuli, the neuron covers the stimulus with its whole response repertoire regardless of the stimulus entropy, with the information rate being limited by the noise of the stimulus and the neural hardware.

Purpose: To study the effect of body temperature on the murine electroretinogram (ERG). Methods: The corneal ERG elicited by a strobe flash from dark-adapted mice was recorded using a saline wick electrode while measuring rectal temperature continuously. The mouse was placed within a cylindrical coil of tubing through which water circulated from a temperature controlled bath. The body temperature of the mouse was changed stepwise between 30 and 37 °C. Results: ERGs of approximately normal configuration were recorded at body temperature ranging between 30 and 37 °C. The maximum amplitude of the a- and b-waves varied linearly with temperature. The rate of change of b-wave amplitude was about 100 μV/degree. At 30 °C, maximum b-wave amplitude was about 400 μV; at 37 °C it was about 1000 μV. A change in body temperature produced a rapid change in ERG amplitude. Conclusion: The murine ERG is very sensitive to changes in temperature. In order to monitor the ERG accurately over time, continuous recording of body temperature is essential.

Since the caldera-forming eruption of Miyakejima Volcano in 2000, low-frequency (LF) earthquakes have occurred frequently beneath the caldera. Some of these LF earthquakes are accompanied by emergent infrasonic pulses that start with dilatational phases and may be accompanied by the eruption of small amounts of ash. The estimated source locations of both the LF earthquakes and the infrasonic signals are within the vent at shallow depth. Moreover, the maximum seismic amplitude roughly correlates with the maximum amplitude of the infrasonic pulses. From these observations, we hypothesized that the infrasonic waves were excited by partial subsidence within the vent associated with the LF earthquakes. To verify our hypothesis, we used the infrasonic data to estimate the volumetric change due to the partial subsidence associated with each LF earthquake. The results showed that partial subsidence in the vent can well explain the generation of infrasonic waves.

The relationship between European winter temperature spatial and temporal modes of variability and the North Atlantic Oscillation (NAO) has been studied during the period 1852–1997. Temporal modes of variability of the NAO and temperatures are analysed using wavelet transform. Results show that the NAO presents a strong non-stationary behaviour. The most important feature is the existence of a quasi-periodic oscillation, with a period between 6–10 years and maximum amplitude of eight years, during the periods 1842–1868 and 1964–1994. Between 1875 and 1939 the spectra of the NAO is almost white. The possible relationship between the occurrence of extreme events of the NAO and its spectral behaviour has been analysed. The results indicate that quasi-periodic oscillations in the NAO do not lead to more extreme episodes, but rather that an extreme value of the oscillation is more likely to persist for few years. Particularly energetic modes of coherent variability between temperature and NAO are found between 2–6 years for 1857–1879 and 1978–1984, and between 6–10 years from 1961 to 1991. The relationship between the NAO and temperatures as a function of the state of the oscillation has been studied using composites. Empirical evidence has been found suggesting that winter temperatures, in a great part of the study area, do not vary in a linear manner with respect to phase and intensity of the NAO. Regions in the study area differ in sensitivity to changes in the NAO. The spatial patterns of variability of the temperatures are found to be independent of the NAO spectra.

Stepped frequency signal is often used to synthesize high-resolution range profile, but redundant high-resolution range profile exists before synthesis. Two methods have been given to extract target from overlapped high-resolution range profile and analyzed to show how spurious peaks appear. This paper provides a reverse-count algorithm to resolve the problem of spurious peaks for moving target. This proposed method selects the peak with maximum amplitude as the extracted target and gets its position by using the number of samples prceding before the present sample position and the number of high-resolution range cell of the target. This proposed method is compared with the already given method and the result shows the ability of the proposed method to remove spurious peaks, it provides the foundation for high-resolution range profile.

Two nonlinear methods are employed for the prediction of the maximum amplitude for solar cycle 23 and its declining behavior. First, a new heuristic method based on the second derivative of the (conveniently smoothed) sunspot data is proposed. The curvature of the smoothed sunspot data at cycle minimum appears to correlate (R ≃ 0.92) with the cycle's later-occurring maximum amplitude. Secondly, in order to predict the near-maximum and declining activity of solar cycle 23, a neural network analysis of the annual mean sunspot time series is also performed. The results of the present study are then compared with some other recent predictions.

Precursor methods for the prediction of maximum amplitude of the solar cycle have previously been found to provide the most reliable indication for the size of the following cycle, years in advance. In this paper, we evaluate several of the previously used geomagnetic precursor methods and some new ones, both as single-variate and multivariate regressions. The newer precursor methods are based on the size of the geomagnetic index maximum, which, since cycle 12, has always occurred during the declining portion of the solar cycle, usually several years before subsequent cycle minimum. These various precursor techniques are then applied to cycle 23, yielding the prediction that its maximum amplitude should be about 168 ± 15 (r.m.s.), peaking sometime in 1999–2000.