Discontinuous Research Articles

Seasonal and Annual Trends in Australian Minimum/Maximum Daily Temperatures

Seasonal and annual trends in Australian minimum and maximum temperatures were studied. Records of daily minimum and maximum temperatures averaged over each month, extending as far back as 1856 were examined. Over 1/2 million monthly temperature values were retrieved from the Australian Bureau of Meteorology for 299 stations. Each station had an average of 89 years of observations. Significant step discontinuities affected the maximum temperature data in the 19th century when Stevenson screens were installed. The temperature trends were found after such spurious data were removed and averaged over all stations. The resulting trend in the minimum (maximum) daily temperature was 0.67 ± 0.19 (0.58 ± 0.26) oC per century for the period 1907-2014. Decadal fluctuations were evident in the maximum daily temperature with most of the increase occurring in the late 20th century. The minimum and maximum daily temperature trends were also found for the various seasons. The minimum daily temperature trend exceeded the maximum daily temperature trend for all seasons except during June to August. The largest increases in minimum temperature as well as the smallest maximum temperature increases were found for the region north of 30 oS latitude and east of 140 oE longitude. There was also evidence that urban stations had greater increases in maximum daily temperature than those located in a rural environment.

Measurements and simulations of wakefields at the Accelerator Test Facility 2

Wakefields are an important factor in accelerator design, and are a real concern when preserving the low beam emittance in modern machines. Charge dependent beam size growth has been observed at the Accelerator Test Facility (ATF2), a test accelerator for future linear collider beam delivery systems. Part of the explanation of this beam size growth is wakefields. In this paper we present numerical calculations of the wakefields produced by several types of geometrical discontinuities in the beam line as well as tracking simulations to estimate the induced effects. We also discuss precision beam kick measurements performed with the ATF2 cavity beam position monitor system for a test wakefield source in a movable section of the vacuum chamber. Using an improved model independent method we measured a wakefield kick for this movable section of about $0.49\text{ }\text{ }\mathrm{V}/\mathrm{pC}/\mathrm{mm}$, which, compared to the calculated value from electromagnetic simulations of $0.41\text{ }\text{ }\mathrm{V}/\mathrm{pC}/\mathrm{mm}$, is within the systematic error.

ОБ ОПЕРАТОРАХ С РАЗРЫВНОЙ ОБЛАСТЬЮ ЗНАЧЕНИЙ

ОБ ОПЕРАТОРАХ С РАЗРЫВНОЙ ОБЛАСТЬЮ ЗНАЧЕНИЙ

Optimization Using Boundary LookupJump Point Search

Cache-based path-finding algorithms lose much of their advantage in dynamic environments where fast online search algorithms are required. Jump point search (JPS) is such a fast algorithm. It works by eliminating most map nodes from evaluation during path expansion. Boundary lookup jump point search (BL–JPS) is a modification that improves the speed of JPS. BL–JPS records the positions of obstacle boundaries and uses these via direct lookup to eliminate much of the iteration involved in searching for jump points in the JPS algorithm. Two sets of experiments are presented, demonstrating the effects of BL–JPS in both static and dynamic environments. The effects of different approaches to cache rebuilding for JPS+ in dynamic environments are also evaluated. Results show that BL–JPS is generally much faster than JPS. It is slower than JPS+ in static environments, but in dynamic environments, BL–JPS outperforms JPS+ for a single search. When multiple paths are searched, the effects of cache rebuilding gradually dominate the effects of search speed, resulting in JPS+ again becoming faster. However, combining JPS+ with BL–JPS provides a very fast path-finding algorithm (BL–JPS+) that outperforms JPS+ over a range of map types and numbers of paths searched.

The Influence of Sensitivity Field of Dual Transducer Probes on Accuracy of Discontinuity Sizing and Evaluation in Terms of Testing of Forgings According to EN 10228-3

Abstract The article presents results of research on the impact of sensitivity distribution of double transducer probes, which are often used in non-destructive ultrasonic testing of components such as forgings. Distribution of sensitivity measured in two orientations, parallel and perpendicular to the plane of separation of a double transducer probe has been tested and analyzed. A significant influence of orientation of a probe on echo envelope of an artificial point discontinuity has been studied. It has revealed great differences in length and shape of an echo envelope, depending on a type of probe and orientation of a probe separation plane to the moving direction. Eventually, the analysis of practical consequences of dual transducer probes usage for characterization of a type, dimensioning and evaluation of internal discontinuities, in accordance to the methodology specified in EN 10228, has been conducted.

Graphene-based waveguide resonators for submillimeter-wave applications

Utilization of graphene covered waveguide inserts to form tunable waveguide resonators is theoretically explained and rigorously investigated by means of full-wave numerical electromagnetic simulations. Instead of using graphene-based switching elements, the concept we propose incorporates graphene sheets as parts of a resonator. Electrostatic tuning of the graphene surface conductivity leads to changes in the electromagnetic field boundary conditions at the resonator edges and surfaces, thus producing an effect similar to varying the electrical length of a resonator. The presented outline of the theoretical background serves to give phenomenological insight into the resonator behavior, but it can also be used to develop customized software tools for design and optimization of graphene-based resonators and filters. Due to the linear dependence of the imaginary part of the graphene surface impedance on frequency, the proposed concept was expected to become effective for frequencies above 100 GHz, which is confirmed by the numerical simulations. A frequency range from 100 GHz up to 1100 GHz, where the rectangular waveguides are used, is considered. Simple, all-graphene-based resonators are analyzed first, to assess the achievable tunability and to check the performance throughout the considered frequency range. Graphene–metal combined waveguide resonators are proposed in order to preserve the excellent quality factors typical for the type of waveguide discontinuities used. Dependence of resonator properties on key design parameters is studied in detail. Dependence of resonator properties throughout the frequency range of interest is studied using eight different waveguide sections appropriate for different frequency intervals. Proposed resonators are aimed at applications in the submillimeter-wave spectral region, serving as the compact tunable components for the design of bandpass filters and other devices.

Effect of hydrogen on endotoxin-induced expression of zonula occludens-1 in human colon epithelial cells

Objective To investigate the effect of hydrogen on endotoxin-induced expression of zonula occludens-1 (ZO-1) in human colon epithelial cells (Caco-2 cells). Methods Caco-2 cells were cultured routinely, seeded in Transwell chambers or wells, and randomly divided into 4 groups (n=45 each) using a random number table: control group (group C); hydrogen-rich culture medium group (group H); endotoxin group (group E); hydrogen-rich culture medium + endotoxin group (group HE). The cells were cultured in high-glucose DMEM culture medium in group C. The cells were incubated in hydrogen-rich culture medium containing hydrogen 0.6 mmol/L in group H. The cells were incubated in high-glucose DMEM culture medium containing 50 μg/ml lipopolysaccharide in group E. The cells were incubated in hydrogen-rich culture medium containing 50 μg/ml lipopolysaccharide and 0.6 mmol/L hydrogen in group HE.Transepithelial electrical resistance (TEER) was measured before incubation or culture, and at 6, 12 and 24 h of incubation or culture.The viability of Caco-2 cells was measured by methyl thiazolyl tetrazolium assay at 24 h of incubation or culture.The expression of ZO-1 mRNA in Caco-2 cells was determined using real-time reverse transcriptase polymerase chain reaction at 6, 12 and 24 h of incubation or culture.The distribution of ZO-1 in Caco-2 cells was observed by immunofluorescence at 24 of incubation or culture. Results Compared with group C, TEER was significantly decreased at 6, 12 and 24 h of incubation or culture, and the expression of ZO-1 mRNA was significantly down-regulated in E and HE groups (P 0.05). Compared with group E, TEER was significantly increased at 6, 12 and 24 h of incubation or culture, and the expression of ZO-1 mRNA was significantly up-regulated in group HE (P<0.05). The distribution of ZO-1 protein in cell membrane became discontinuous, and the distribution of ZO-1 protein in cytoplasm was significantly increased in group E. Compared with group E, the distribution of ZO-1 protein in cell membrane was significantly increased and gradually became continuous, and the distribution of ZO-1 protein in cytoplasm was significantly decreased in group HE. Conclusion The mechanism by which hydrogen reduces the damage to human colon epithelial cell barrier is related to up-regulation of ZO-1 expression and improvement in the redistribution of ZO-1 protein. Key words: Hydrogen; Endotoxemia; Tight junctions; Intestines

Large deviation principle for one-dimensional SDEs with discontinuous coefficients

We establish the large deviation principle for solutions of one-dimensional SDEs with discontinuous coefficients. The main statement is formulated in a form similar to the classical Wentzel--Freidlin theorem, but under the considerably weaker assumption that the coefficients have no discontinuities of the second kind.

A study on the migrations of murine rodents in urban environments

The migrations of murine rodents and their capacity for overcoming various obstacles in urbanized environments have been analyzed. Animals marked with tetracycline were captured at different distances from the marking plot. The maximum distance of movement along a straight line was 2030 m for the pygmy wood mouse (Sylvaemus uralensis Pall.) and 430 m for the bank vole (Clethrionomys glareolus Schr.). It was revealed that the pygmy wood mouse can successfully cross various types of landscape discontinuities which can act as movement barriers.

Lamb wave propagation in a plate with step discontinuities

Ultrasonic Lamb waves are affected by structural discontinuities (e.g. stiffeners, ribs or joints), and it is necessary to understand the quantitative characteristics of their influence on the waves so that the structural features are not misidentified as defects in nondestructive evaluation (NDE) applications. In this paper, the benchmark problem of Lamb wave reflection at a free end as well as the interaction of Lamb waves with upward and downward step discontinuities is solved using an analytical approach. The free-end problem is considered to show the influence of the decaying waves on the power flow in the plate. In all problems, a near-field solution is obtained, and power flows past the cross-sections of the plate are evaluated. Furthermore, amplitude spectra and results for different step sizes are presented. The analytically derived results are compared with those from transient finite element simulations, showing good agreement.

Hybrid-state driven autonomous control for planar bipedal locomotion

The focus of this paper is on the development of a human inspired autonomous control scheme for a planar bipedal robot in a hybrid dynamical framework to realize human-like walking projected onto sagittal plane. In addition, a unified modelling scheme is presented for the biped dynamics incorporating the effects of various locomotion constraints due to varying feet-ground contact states, unilateral ground contact force, contact friction cone, passive dynamics associated with floating base etc. along with a practical impact velocity map on heel strike event. The autonomous control synthesis is formulated as a two-level hierarchical control algorithm with a hybrid-state based supervisory control in outer level and an integrated set of constrained motion control primitives, called task level control, in inner level. The supervisory level control is designed based on a human inspired heuristic approach whereas the task level control is formulated as a quadratic optimization problem with linear constraints. The explicit analytic solution obtained in terms of joint acceleration and ground contact force is used in turn to generate the joint torque command based on inverse dynamics model of the biped. The proposed controller framework is named as Hybrid-state Driven Autonomous Control (HyDAC). Unlike many other bipedal control schemes, HyDAC does not require a preplanned trajectory or orbit in terms of joint variables for locomotion control. Moreover, it is built upon a set of basic motion control primitives similar to those in human walk which provides a transparent and easily adaptable structure for the controller. These features make HyDAC framework suitable for bipedal walk on terrain with step and slope discontinuities without a priori gait optimization. The stability and agility of the proposed control scheme are demonstrated through dynamic model simulation of a 12-link planar biped having similar size and mass properties of an adult sized human being restricted to sagittal plane. Simulation results show that the planar biped is able to walk for a speed range of 0.1–2 m/s on level terrain and for a ground slope range of +/−20 deg for 1 m/s speed.

Effects of area discontinuity at nozzle inlet on the characteristics of self-resonating cavitating waterjet

The current research on self-resonating cavitating waterjet(SRCW) mainly focuses on the generation mechanism and structure optimization. Researches relating to the influences of disturbances at nozzle inlet on the characteristics of the jet are rarely available. In order to further improve the performance of SRCW, effects of area discontinuity(enlargement and contraction) are experimentally investigated using three organ-pipe nozzles. Axial pressure oscillation peak and amplitude as well as aggressive erosion intensity of the jet are used to evaluate the effects. The results reveal that area enlargement and contraction affect the peak differently, depending on the inlet pressure, nozzle geometry, and standoff distance; while area contraction always improves the amplitude regardless of these factors. At inlet pressures of 10 MPa and 20 MPa, area discontinuity improves the peak at almost all the testing standoff distances, while this only happens at smaller standoff distances with the inlet pressure increased to 30 MPa. The capability of area discontinuity for improving the amplitude is enhancing with increasing inlet pressure. Moreover, the cavitation erosion ability of the jet can be largely enhanced around the optimum standoff distance, depending on the type of area discontinuity and nozzle geometry. A preliminary analysis of the influence of area discontinuity on the disturbance waves in the flow is also performed. The proposed research provides a new method for effectively enhancing the performance of SRCW.

A stability assessment of the rockfall problem around the Gökgöl Tunnel (Zonguldak, Turkey)

The stability of rock slopes is an important area of interest in civil and mining engineering. This study investigated rockfall occurring around the Gokgol tunnel along the Zonguldak-Ankara roadway. Extensive field studies, including determination of geological description of the rock mass, scan-line surveys on discontinuities, identification of slope profiles, measurement of actual fallen block dimensions, and sampling procedures, were carried out. The study area and its surroundings are part of a Lower Carboniferous limestone formation. The assessments based on field studies indicated that two joint sets and a bedding plane were the main types of discontinuity. Two slope profiles were then created by considering the most frequently encountered rock fall events. The present study aimed to investigate the rockfall potential in this area by means of numerical analyses. For this purpose, RocFall software based on the lumped-mass method was utilized. Based on these analyses, traffic safety is threatened by potential rockfall. In Case I, a 30 % portion of the falling blocks reached the side of the main road, while about 70 % of them remained on the slope. However, falling blocks reached the end of the road in Case II. The study area requires some protection measures, such as the construction of retaining barriers and steel mesh to hold small size rock blocks. As a result, barrier heights to hold falling blocks were calculated as 0.5 m and 4 m for Case I and Case II, respectively. Barrier heights sufficient to hold falling rocks were determined using numerical analysis. In Case II, from such analyses, the energy required for a protection barrier for 1000 kg was found to be 200 kJ.

A real-time digital calibration scheme for the cyclic ADC

A digital calibration scheme to correct the nonlinearity caused by finite amplifier gain and capacitor mismatch for the cyclic analog-to-digital converter (ADC) is presented. The calibration block of correcting the weight of the jumping points is implemented in which adders and registers are utilized without multipliers to reduce the silicon area cost. Each calibration block is shared by five ADCs. Ten switches are added into the 1.5-bit multiplying digital-to-analog converter to choose the test input signal and set the value of the most significant bit for measuring the heights of the jumping points. The capacitor mismatch and gain errors are measured as one error, and then the weight of the jumping points is compensated in the digital domain to improve the linearity of the ADC. Designed in a 0.18μm CMOS technology, the silicon area cost of each ADC is 0.03×1.7mm2 and the power consumption is 0.56mW at a supply voltage of 1.8V. The simulation results show that the calibration improves SNDR to 83.73dB from 55.13dB with 1% capacitance mismatch, and the calibration needs three conversion cycles which makes it real-time to obtain the changing error parameters during normal operation.

The driving force of action and the psychology of doing nothing

Abstract My article discusses the psychological factors determining the driving force of human activity as well as the driving force of doing nothing. The discussion is related to the personal resources characteristics (personality, the type of mind, operational style), personal coping strategies with the pressures of time (procrastination, indecisiveness), an autonomous vs. non-autonomous reality creating style (passion, passivity), and anticipatory identity capital modelling by capitalizing on one’s own advantages and proactivity. The driving force of human activity and doing nothing presented in the article is discussed from a psychological perspective as a multidimensional phenomenon. Firstly, it is discussed as a preconditioned personality trait, secondly as a contextually determined search for exiting from a difficult situation by delaying a decision, thirdly as an agentural creation of energy program of action (passion, apathy), and at the end as an agentural production of the self-advantages through proactivity. My article also reviews basic types of discontinuity and personality types related to them. These five discontinuity types are: 1 – place discontinuity, 2 – situation discontinuity, 3 – meanings and values discontinuity, 4 – context discontinuity, 5 – projective discontinuity.

MORAL AND EDUCATIONAL PRINCIPLES IN THE WORKS OF IMAM KHOMEINI

The present article aims at studying the moral and educational principles and basics from Imam Khomeini’s viewpoint and seeks to answer to these questions: what is the position of the moral and educational principles in the works and ideas of Imam Khomeini? What is the position of moral and educational principles and methods in the works of Imam Khomeini? What are elements of anthropological education from Khomeini’s viewpoint? This research is of descriptive-analytical method. This article reviewing works and ideas of Imam Khomeini attempts to extract moral and educational principles from his perspective. The findings indicate that Imam Khomeini regards education as an important function in education system of Islamic society based on rules including principle of priority of self-correction over correcting others, principle of self-refinement priority over teaching, the principle of training continuity, the principle of repetition and indoctrination, the principle of directionality of training, and the principle of attractionism. Also, goals of education from Imam’s idea includes as following. Natural growth which is growth in physic and biology, intellectual growth which is fostering reasoning is spiritual growth and nurturing movements of heart and imagination, scientific and political development. Moreover, in order to achieve a full human education from Imam Khomeini’s viewpoint it should be based on methods as 1. Way of thinking 2. How to stimulate awareness and insight 3 Way of emotional motivation 4 Lessoning way 5 Reverence and encouragement 6 Repetition and indoctrination 7 How to use enemy 8 Calculation method 9 Advice and benevolence method 10 Pattern. Anthropological foundations of education in Imam Khomeini’s viewpoint are: discontinuous intrinsic relationship with God, truth- and justice-seeking, in search of perfection and love of completeness, desire to happiness and eternal prosperity, and a will to benevolence and freedom.

Importance Sampling for Option Greeks with Discontinuous Payoffs

The Greeks are derivatives of option price with respect to market parameters and play an important role in financial risk management. Among various simulation methods for estimating the Greeks, the...

Long-period irregular pulsations under the conditions of a quiet magnetosphere

Simultaneous observations of high-latitude long-period irregular pulsations at frequencies of 2.0–6.0 mHz (ipcl) and magnetic field disturbances in the solar wind plasma at low geomagnetic activity (Kp ~ 0) have been studied. The 1-s data on the magnetic field registration at Godhavn (GDH) high-latitude observatory and the 1-min data on the solar wind plasma and IMF parameters for 2011–2013 were used in an analysis. Ipcl (irregular pulsations continuous, long), which were observed against a background of the IMF Bz reorientation from northward to southward, have been analyzed. In this case other solar wind plasma and IMF parameters, such as velocity V, density n, solar wind dynamic pressure P = ρV2 (ρ is plasma density), and strength magnitude B, were relatively stable. The effect of the IMF Bz variation rate on the ipcl spectral composition and intensity has been studied. It was established that the ipcl spectral density reaches its maximum (~10–20 min) after IMF Bz sign reversal in a predominant number of cases. It was detected that the ipcl average frequency (f) is linearly related to the IMF Bz variation rate (ΔBz/Δt). It was shown that the dependence of f on ΔBz/Δt is controlled by the α = arctan(By/Bx) angle value responsible for the MHD discontinuity type at the front boundary of magnetosphere. The results made it possible to assume that the formation of the observed ipcl spectrum, which is related to the IMF Bz reorientation, is caused by solar wind plasma turbulence, which promotes the development of current sheet instability and surface wave amplification at the magnetopause.

Conjugate Problem for a Third Order Equation with Multiple Characteristics and a Positive Function at the Higher Order Derivative

We establish the existence and uniqueness of a regular solution to the conjugate (generalized diffraction) problem for the equation ut − h(x)u xxx + c(x, t)u = f(x, t), where h(x) is positive and can have discontinuity of the first kind at the point x = 0.

Application of amplitude-integrated electroencephalography in term neonates with brain injury

Objective To explore the value of amplitude-integrated electroencephalography(aEEG) in diagnosis and prognosis in term newborns with brain injury. Methods One hundred and thirty consecutive patients with brain injury admitted in NICU were prospectively enrolled in the study from Nov 2013 to Apr 2015.The monitoring of aEEG was done at 1d, 4d, 7d, respectively.Clinical data were collected and compared with the result of aEEG. Results All the cases of newborns with abnormal aEEG background: discontinuous voltage(109 cases), continuous low voltage(12 cases), flat(4 cases). The epileptic activity were recorded in 33 cases, and 15 cases showed burst-suppression; sleep wake cycle: mature(32 cases), immature(54 cases), no sleep wake cycle(39 cases). The judgment of abnormal level: 70 cases had mildly abnormal aEEG, severe abnormalities 60 cases, and no significant difference in different types of diseases(χ2=6.176, P=0.19). Recent prognosis: the death of mild and severe abnormalities were 1 case, 12 cases, respectively, there were significant differences(χ2=12.76, P<0.001). Developmental quotient(DQ) of these newborns were followed up for more than 6 months, and there were significant differences in mild, severe abnormal aEEG in them with DQ≥85 and DQ<85(χ2=33.195, P<0.001). The sensitivity of aEEG in severe abnormal aEEG was 68.75%, the specificity was 78.68%, and the positive and negative predictive values of aEEG were 77.19% and 70.58%, respectively.The results of aEEG classification and sleep wake cycle were correlated with the prognosis of the patients(r=0.505, 0.507, respectively, P<0.001). Conclusion aEEG can be used to monitor brain function, and it is helpful to evaluation of early diagnosis and prognosis. Key words: Electroencephalography; Amplitude-integrated electroencephalography; Brain injury; Infant, newborn; Prognosis