Time Interval Measurement Research Articles

Time, Equilibrium, and General Relativity

Considered is "time as an interval” including time from the past and from the future, in contrast to time as a moment. Equilibrium as the basis for a description of changing properties in physics is understood to depend on the "mean velocity theorem”, while a "time” of equilibrium resembles a center of weight. This turns out to be a good method to derive properties for any function of time t including space coordinates q(t) and expressions for the time dependent Hamiltonian. Introduced are derivatives depending on time intervals instead of time moments and with these a new relation between the Lagrangian L and the Hamiltonian H. As an application introduced is a step by step method to integrate stationary state "local” time interval measurements to beyond "locality” in General Relativity. Because of limits on the resulting time interval measures, this allows for a probabilistic interpretation for quantities that have these intervals as time domain. Thus, these measures are interesting in both a GR as a QM sense. Another application of time interval is the discussion of the measurement of starlight radiation energy and QM wave packet collapse as an example of a time dependent Hamiltonian. Finally, a relation between starlight frequency, metric and space- and time intervals is discussed. The time intervals also question the time reversal symmetry of GR.

9 ps TDC based on multiple sampling in 0.18 μm complementary metal–oxide–semiconductor

A high-precision measurement method, based on multiple sampling, is proposed for the time interval of two signals in this study. A time interval measurement circuit integrated into the time-to-digital converter (TDC), is designed based on this high-precision measurement method. In the TDC, the authors use two identical delay lines as the holding module to ensure the two signals with a constant time interval. The TDC samples the two signals multiple times by a clock signal, whose period is shorter than that of the delay line. Consequently, the problem of limited resolution caused by a mismatch between delay lines in the delay-line structure can be avoided, and the precision of the output can be improved. The proposed TDC is designed and simulated in Semiconductor Manufacturing International Corporation (SMIC) 0.18 μm complementary metal-oxide-semiconductor process. Simulation results show that the differential non-linearity and the integral non-linearity are always less than one least significant bits. The proposed TDC achieves input dynamic range of 0-32.13 ns and time resolution of 9 ps.

A Novel High-Precision Synchronous Sampling Mechanism for Distributed Test System Based on Optical Fiber Network and Low-Cost Field-Programmable Gate Array

In this paper, we propose a distributed test system based on optical fiber network with multiple devices. In order to resolve the data sampling synchronicity problems, a novel synchronous sampling mechanism is developed to achieve high-precision sampling synchronicity among data acquisition devices with relatively low-cost hardware. First, we present the design of the system based on optical fiber network and the mechanism implemented in Field-Programmable Gate Array (FPGA) devices. Then, the device clocks are calibrated to run on a same frequency using a clock-disciplining algorithm for hardware implementation. In addition, propagation delays, which are used for the synchronous errors compensation during data analysis, are precisely measured using a high-precision time interval measurement approach based on delay-chain loop comparison method. A series of experiments on a real test system demonstrate the effectiveness of the proposed models and methods, and the mechanism has been employed in a general-purpose reprogrammable device cyclone-II (Altera).

Activity Test Oinment Extract Ambon Banana Peels (Musa Paradisiaca L.) with Rabbit’s (Orycctolagus Cuniculus) Combustio (Minor Burns)

Combustio (Minor Burns) are a form of tissue damage or loss caused by contact with heat sources such as fire, hot water, chemicals, electricity and radiation. This study aims to determine the administration of Ambon banana extract to cure burns. The extract is made by meseration using 70% ethanol. This study used rabbits divided into 5 groups: positive control group (mebo ointment), negative control group which (not treated) and 3 test groups given Ambon banana peel ointment with varying concentrations (5%, 10%, and 15%) on the basis of hydrocarbon ointments. The method of making mild burns using the intervention method by administering ethan extract ointment ol the peel of Ambon banana for 15 days. Parameters observed included evaluation of ointment, identification of tannin compounds, and percentage of healing of burns. The results of the evaluation of the ointment containing the extract of ambon banana peel concentrated 5%, 10% and 15% fulfilled the requirements of the organoleptic test, homogeneity, pH, spreadability and stickiness. The results of the identification of compounds of ambon banana peel positively contain tannins characterized by the presence of a blackish green color. The results of analysts based on Friedman’s hypothesis test revealed that the value of p <0.05 then there was a difference in healing of burns in the group of time interval measurements and healing of burns. Where the healing of burns is the fastest, namely at the concentration of F3 ointment 15% with a percentage of wound healing 75% compared to positive control mebo with a healing percentage of 61.5%. It can be concluded that the Ambon banana peel extract ointment has healing activities for burns.

Vitamin D serum levels in multiorgan failure critically ill patients undergoing continuous renal replacement therapies.

Severe vitamin D deficiency in critically ill patients is linked to mortality. There are no scientific data regarding vitamin D status in critically ill patients undergoing continuous renal replacement therapies. We aimed to measure vitamin D serum levels in critically ill patients with multi-organ failure undergoing continuous renal replacement therapies. Vitamin D serum measurements in 12-hour time intervals were performed in 20 patients undergoing continuous renal replacement therapies through continuous veno-venous haemodiafiltration (the study group). The results were then compared with the historical control group (20 patients without renal replacement therapy). In the control group the median vitamin D level initially decreased, then stabilised around the fourth and fifth measurement, after which it appeared to increase unevenly. In the study group the median vitamin D level decreased considerably, and then stabilised around the third measurement. Although the differences between groups gradually increased for the last three measurements, there was insufficient evidence to indicate that they were statistically significant (P > 0.05). Significant correlations were found between the time of measurement and the level of vitamin D in the study (R = -0.31, P = 0.0002) and control groups (R = -0.18, P = 0.0341). Vitamin D serum levels decline rapidly during the course of critical illness in patients undergoing continuous renal replacement therapies. No statistically significant differences in the levels of vitamin D between the study and control groups were found.

Pre-calibration of the phase interpolator of a precision time interval meter

The problems of precision measurements of time intervals are considered, the results of which are necessary, for example, to assess the metrological characteristics of the structural complexes of space navigation systems. A precision time interval meter has been designed. The relationship between the meter readings and the size of the measured value is established. A technique for preliminary calibration of a phase interpolator with an uneven quantization step from the composition of a precision time interval meter was developed and tested. The optimal value of the reference frequency was selected and the optimal size of the measuring matrix, consisting of logic gates connected in series, was calculated. The degree of influence of the crystal temperature of the FPGA integrated circuit on the operation of the phase interpolator is determined. The requirements for test signals were developed and the possibility of using the reference signals of the secondary standards of time and frequency (for example, the State secondary standard of units of time and frequency VET 1-7) during the preliminary calibration of the phase interpolator was evaluated. Special software has been developed for determining the boundaries of the sub-quanta of the phase interpolator with a resolution of one picosecond, and the probability density functions of the transition process from one subquantum to the next are calculated. The requirements for the spectral composition of the frequency of the reference signal are given and the frequency detuning of the test signal relative to the reference is determined. Verification of the developed methodology for preliminary calibration of the temporal position of the phase transitions of the interpolator was carried out by repeated calibrations and comparison of the results.

Design and development equipment to measure the motion quantities of an object that moving in air or in fluid

We have developed an equipment for time interval measurement of an object that move free fall in air or in water by using microprocessor Arduino as a clock timer and is controlled by pair of laser diode and photo diode. By this technique, the main problem how to find the equation of motion can be obtained. The results show that the equipment work well. The equipment is able to measure time interval of an object that move free fall in air or in water which position change up to 10 cm. By positioning the pair of laser diode and photo diode in six different heights we can plot the position as a function of time. By the aid of a personal computer software it is easily to obtain the equation of motion of the object move both in air or in water. This equipment is useful for high school and under graduate university student to measure the gravity intensity and to study the drag force in fluid.

Improving emergency call detection of Out-of-Hospital Cardiac Arrests in the Greater Paris area: Efficiency of a global system with a new method of detection

AimThe detection of cardiac arrests by dispatchers allows telephone-assisted cardiopulmonary resuscitation (t-CPR) and improves Out-of-Hospital Cardiac Arrest (OHCA) survival. To enhance the OHCA detection rate, in 2012, the Paris Fire Brigade dispatch center created an original technique called "Hand On Belly" (HoB). The new algorithm that resulted has become a central point in a broader program for dispatch-assisted cardiac arrests. MethodsThis is a repeated cross-sectional study with retrospective data of four 15-day call samples recorded from 2012 to 2018. We included all calls from OHCAs cared for by Basic Life Support (BLS) teams and excluded calls where the dispatcher was not in contact directly with a witness. The primary endpoint was the successful detection of an OHCA by the dispatcher; the secondary endpoints were successful t-CPR and measurements of the different time intervals related to the call. Logistic regressions were performed to assess parameters associated with detecting OHCAs and initiating t-CPR. ResultsFrom 2012 to 2018, among the detectable OCHAs, the proportion correctly identified increased from 54% to 93%; the rate of t-CPRs from 51% to 84%. OHCA detection and t-CPR initiation were both associated with HoB breathing assessments (adjustedOR: 89, 95%CI: 31–299, and adjustedOR: 11.2, 95%CI: 1.4–149, respectively). Over the study period, the times to answering calls and the time to sending BLS teams were shorter than those recommended by international guidelines; however, the times to OHCA recognition and starting t-CPR delivery were longer. ConclusionsThe HoB effectively facilitated OHCA detection in our system, which has achieved very high performance levels.

Time Interval Measurement in the Picosecond Accuracy

A model and a laboratory method were developed for determining the major systematic errors affecting time interval measurement (TIM) accuracy. The laboratory method investigates the optimum trigger level for the high slew rate timing pulses that achieves the highest TIM accuracy. The overall errors due to the measurement setup and the trigger level, at which the measurements are executed, are the most considerable sources of systematic errors. Previously these error sources were modeled. In this study the model was modified for estimating more precisely the systematic errors contributed by the measurement setup. Also a laboratory method was experienced to determine the optimum trigger level for the timing pulses. Applying these methods achieve a TIM accuracy in the picosecond range.

Estimating confined aquifer parameters using a simple derivative-based method

The confined aquifer parameters, transmissivity and storage coefficient, are commonly determined using the pumping tests. Several methods have been developed to estimate confined aquifer parameters using pumping tests, but different methods suffer from different drawbacks. Those methods that use the truncated Theis well functionw(u), apply just early or late drawdowns, depending on the case, to estimate the aquifer parameters. Those methods, such as Theis (1935), that use non-truncated well functionw(u), can apply all drawdown data for aquifer parameter estimation but may still suffer from subjectivities such as personsal judgment in curve matching, time-consuming procedure and requiring values for Theis well function, w(u), and its argument u(u=r2S4Tt). The aim of this study is to present a new method to overcome the aforementioned drawbacks and subjectivities involved in available published methods. In this paper, a simple derivative-based method is presented to estimate confined aquifer parameters applicable for entire drawdowns during the pumping period. The time derivative of drawdowns relate non-linearly with pumping timet, and therefore, aquifer parameters are estimated using developed equations based on the least squares optimization approach. The method is applied to three sets of synthetic, published and field data and results show that the estimation accuracy is acceptable. The drawdown time interval measurement has a marginal effect on parameters estimation due to the analytical basis of derivative calculations. The method does not require construction of graphs, and numerical calculations may be performed on a calculator to determine the aquifer parameters on site. It does not require curve matching, initial guess of the parameters and values of w(u) and u.

Clinical value of myocardial performance index in patients with isolated diastolic dysfunction

AimsThe Doppler-derived myocardial performance index (MPI) has been considered as a diagnostic and prognostic Doppler marker for many different clinical conditions. The purpose of this study was to determine the diagnostic accuracy of traditional Pulsed-wave Doppler (PWD-MPI) and Pulsed-wave tissue Doppler imaging (TDI-MPI) and the degree of agreement between these methods in patients with grade-I diastolic dysfunction (DDI) and a normal ejection fraction.MethodsForty-seven consecutive ambulatory patients with DDI were compared to 51 healthy subjects with normal echocardiograms. All subjects underwent measurement of time intervals and MPI with PWD and pulsed TDI.ResultsTDI-MPI and PWD-MPI were significantly higher in patients with DDI than in control subjects: 0.49 ± 0.14 vs. 0.40 ± 0.09 (P < 0.001) and 0.45 ± 0.11 vs. 0.37 ± 0.08 (P < 0.001), respectively. Cutoff values of TDI-MPI > 0.42 and PWD-MPI > 0.40 identified DDI subjects, with sensitivities of 74 and 64%; specificities of 61 and 69%; positive likelihood ratios of 1.9 and 2.0; and negative likelihood ratios of 0.42 and 0.53, respectively; no significant difference was noted between the areas under the ROC curves of TDI-MPI and PWD-MPI (P = 0.77). Bland-Altman plots showed wide limits of agreement between these indices: − 0.17 to 0.23 in healthy subjects and − 0.24 to 0.32 in DDI patients.ConclusionPWD-MPI and TDI-MPI showed poor clinical agreement and were not reliable parameters for the assessment of left ventricular diastolic function.

Microcontroller-based time interval and correlation measurement for quantum optics experiments

We describe the design, implementation and performance of a compact microcontroller-based time interval/correlation measurement device suitable for characterizing light in quantum optics experiments. It is also suitable for measuring the lifetime of atoms excited by a laser pulse. This correlator is based on measuring the time between the arrival of two consecutive photons and generating a histogram of time between photons. The interferometer is capable of measuring time difference with a resolution of at least 110 ps. The two-photon correlator discussed here was built using an analogue feature within a 16 bit PIC microcontroller whereby the charge on a capacitor is measured. The arrival of the first photon starts the charging and the second photon stops it. The voltage on the capacitor is then proportional to the time difference in the arrival of the two photons. This feature within the microcontroller is called a charge time measurement unit. The system consists of three parts. The first part, made up of two microcontrollers, performs time-to-amplitude conversions using the charge time measurement units and keeps a count of the total number of photons detected by the single-photon detectors. The second part consists of separate circuitry to detect coincidence events using logic gates. The third part consists of a control gateway in the form of another microcontroller between the time measurement microcontrollers and the control software running on a user PC. The system was tested in a lab using simulated signals from a signal generator and in a live quantum optics experiment where our system was compared with a commercial product.

A Chest-Laminated Ultrathin and Stretchable E-Tattoo for the Measurement of Electrocardiogram, Seismocardiogram, and Cardiac Time Intervals.

Seismocardiography (SCG) is a measure of chest vibration associated with heartbeats. While skin soft electronic tattoos (e‐tattoos) have been widely reported for electrocardiogram (ECG) sensing, wearable SCG sensors are still based on either rigid accelerometers or non‐stretchable piezoelectric membranes. This work reports an ultrathin and stretchable SCG sensing e‐tattoo based on the filamentary serpentine mesh of 28‐µm‐thick piezoelectric polymer, polyvinylidene fluoride (PVDF). 3D digital image correlation (DIC) is used to map chest vibration to identify the best location to mount the e‐tattoo and to investigate the effects of substrate stiffness. As piezoelectric sensors easily suffer from motion artifacts, motion artifacts are effectively reduced by performing subtraction between a pair of identical SCG tattoos placed adjacent to each other. Integrating the soft SCG sensor with a pair of soft gold electrodes on a single e‐tattoo platform forms a soft electro‐mechano‐acoustic cardiovascular (EMAC) sensing tattoo, which can perform synchronous ECG and SCG measurements and extract various cardiac time intervals including systolic time interval (STI). Using the EMAC tattoo, strong correlations between STI and the systolic/diastolic blood pressures, are found, which may provide a simple way to estimate blood pressure continuously and noninvasively using one chest‐mounted e‐tattoo.

Aframomum melegueta prevents the ejaculatory complications of propylthiouracil-induced hypothyroidism in sexually experienced male rats: Evidence from intravaginal and fictive ejaculations

ObjectiveHypothyroidism has been claimed to generate sexual dysfunctions such as ejaculatory disorders. Aframomum melegueta is an aphrodisiac plant with pro-ejaculatory properties. We investigated the protective effects of aqueous extract (AE) and methanolic extract (ME) of A. melegueta on the ejaculatory function of hypothyroid male rats. MethodsForty sexually experienced male rats were partitioned into 8 groups (5 rats per group) and treated for 28 d as follows: Group 1, Control; Group 2, propylthiouracil (PTU, 10 mg/kg) + distilled water (DW, 10 mL/kg); Group 3, PTU + 5% Tween 80 (10 mL/kg); Group 4, PTU + bromocriptine (6 mg/kg); Group 5, PTU + AE (20 mg/kg); Group 6, PTU + AE (100 mg/kg); Group 7, PTU + ME (20 mg/kg), and Group 8, PTU + ME (100 mg/kg). On days 0, 7, 14 and 28 of treatment, each male rat was paired with primed receptive female for measurement of ejaculatory latency time (ELT) and post-ejaculatory interval (PEI) for 1.5 h. On day 29, each male rat was urethane-anesthetized and the spinal cord was transected. Thereafter, following urethral/penile stimulations and intravenous injection of dopamine, contractions of the bulbospongiosus muscles and the intraseminal pressure were registered. After these recordings, blood was collected through the catheterization of abdominal artery and plasma was used for thyroid-stimulating hormone (TSH), prolactin and testosterone assays. ResultsPTU-induced hypothyroidism was characterized by a significant elevation (P < 0.001) of plasmatic TSH and prolactin levels, but a decline (P < 0.001) in plasmatic testosterone, compared to untreated group. ELT, PEI, contractions of the bulbospongiosus muscles and the intraseminal pressure were also altered by PTU treatment. On the contrary, A. melegueta extracts elevated testosterone (AE, 100 mg/kg, P < 0.01; ME, 100 mg/kg, P < 0.05) and decreased prolactin (AE, 100 mg/kg, P < 0.05; ME, 20 mg/kg, P < 0.05) levels, compared to corresponding controls. With regard to DW + PTU group, prolactin concentration was lowered (P < 0.05) in rats administered with bromocriptine. Treatment with A. melegueta extracts significantly prevented the lengthening of ELT (P < 0.05) and PEI (P < 0.001). Hypothyroid state also altered the fictive ejaculation by increasing the latency and decreasing the number and frequency of bulbospongiosus muscle contractions. There was also a decrease in the intraseminal pressure. These alterations were significantly (P < 0.05) alleviated in plant extract-treated groups. ConclusionThis study highlighted the ejaculatory disturbance of hypothyroidism in male rats and its prevention with A. melegueta extracts.

Coronary microvascular dysfunction is associated with cardiac time intervals in women with angina and no obstructive coronary artery disease: An iPOWER substudy

Coronary microvascular dysfunction (CMD) may cause angina in the absence of obstructive coronary artery disease (CAD) and increases the risk of future adverse cardiovascular events. Transthoracic Doppler echocardiography (TTDE) with pharmacological stress can assess coronary flow velocity reserve (CFVR), a measure of coronary microvascular function. However, simpler methods would be preferable for diagnosing CMD. Therefore, we examined the relationship between CFVR and cardiac time intervals measured by TTDE in a cohort of women with angina and no obstructive CAD. In a prospective cohort study, we included 389 women with angina, left ventricular ejection fraction>45%, and no obstructive CAD. CMD was defined as CFVR<2.0. The study population was divided into three groups according to cutoff values of CFVR<2, 2≤CFVR≤2.5, and CFVR>2.5. Isovolumic contraction time (IVCT), ejection time (ET), and isovolumic relaxation time (IVRT) were measured by tissue Doppler M-mode, and the myocardial performance index (MPI=(IVCT+IVRT)/ET) was calculated. Coronary microvascular dysfunction was associated with increasing age, hypertension, higher resting heart rate, and lower diastolic blood pressure. Moreover, CMD was associated with higher E/e' ratio (P=0.002) and longer IVCT (P<0.001), higher MPI (P<0.001) and shorter ET (P=0.002), but not with IVRT or conventional measures of left ventricular geometry, mass, and function. In multivariable analysis, longer IVCT (P<0.001) and higher MPI (P=0.002) remained associated with CMD. In women with angina and no obstructive CAD, CMD is associated with longer IVCT and higher MPI indicating a link between CMD and subtle alternations of systolic and combined measures of cardiac time intervals.

64 × 64 GM-APD array-based readout integrated circuit for 3D imaging applications

Using the high sensitivity of the avalanche photodiode (APD) detector operated in the Geiger-mode (GM), an array readout integrated circuit (ROIC) comprising a two-segment time-to-digital converter (TDC) is employed for wide-dynamic time interval measurement, where a 1-bit low-segment TDC is implemented by discriminating a single-phase clock period. The proposed 64 $\times$ 64 GM-APD array ROIC fabricated using Taiwan semiconductor manufacturing company (TSMC) 0.18-$\mu~$m complementary metal oxide semiconductor (CMOS) technology can operate at a maximum frequency of 500 MHz provided by an external phase-locked loop clock. The time resolution is reduced to $<1$ ns along with a maximum range of 4 $\mu~$s; the differential non-linearity (DNL) and integral non-linearity (INL) are restricted to approximately $-$0.15 to 0.15 least significant bit (LSB) and $-$0.3 to 0.32 LSB, respectively; and the power consumption is 490 mW under a frame rate of 20 kHz. The developed ROIC is successfully used in imaging applications in two different ways.

A double threshold correction method for walk error in pulsed laser ranging system

In pulsed laser ranging system, the influence of nonlinear time walk error is inevitable, especially for the fixed-gain receiver channel. Thus, to correct the walk error involved, the alternative method of leading-edge time discrimination for time interval measurement is adopted first and the compensation principle based on the double threshold correction is proposed in this paper. Firstly, the time domain equations are introduced, which is related to bipolar transistor Gummel-Poon (GP) model and circuit structure, and then simplified by numerical analysis. Secondly, by comparison, the important terms in the equations are retained, and then the relationship between the rise time, which can be regarded as the walk error, and the input amplitude is solved. Finally, based on this relationship, the double threshold correction method is given and corrected experimentally which indicates that the walk error can be greatly reduced to 0.337 ns.

A Successive Approximation Time-to-Digital Converter with Single Set of Delay Lines for Time Interval Measurements.

The paper is focused on design of time-to-digital converters based on successive approximation (SA-TDCs—Successive Approximation TDCs) using binary-scaled delay lines in the feedforward architecture. The aim of the paper is to provide a tutorial on successive approximation TDCs (SA-TDCs) on the one hand, and to make the contribution to optimization of SA-TDC design on the other. The proposed design optimization consists essentially in reduction of circuit complexity and die area, as well as in improving converter performance. The main paper contribution is the concept of reducing SA-TDC complexity by removing one of two sets of delay lines in the feedforward architecture at the price of simple output decoding. For 12 bits of resolution, the complexity reduction is close to 50%. Furthermore, the paper presents the implementation of 8-bit SA-TDC in 180 nm CMOS technology with a quantization step 25 ps obtained by asymmetrical design of pair of inverters and symmetrized multiplexer control.

Incertezas na determinação do dia solar verdadeiro: conceitos metrológicos aplicados à astronomia

In this work, we discuss, from a metrological point of view, the measurement of the astronomical time interval, known as true solar which, through History, was a unit of time widely used by mankind. The intention is to apply some concepts of Metrology to a phenomenon strongly related to our lives. The software Stellarium, which allows simulating the movement of the celestial bodies, was employed to measure the duration of the day in regular intervals along one year. The obtained results are presented, compared against the values from the Yearbook of the National Observatory – RJ, analyzed and discussed. Keywords: Metrology; Astrometry; Astronomy, Uncertainty.

A new heart sounds segmentation approach based on the correlation between ECG and PCG signals

During the cardiac cycle, both electrical and mechanical events are present. In fact, the electrocardiogram (ECG) allows the exploration of the electrical activity of the heart, while the phonocardiogram (PCG) constitutes a complementary tool to record the mechanical activity of the heart. The aim of our work is to develop a new approach for heart sounds segmentation based on the correlation between ECG and PCG signals for measurement of systolic time interval. Two different groups of simultaneous recordings of ECG and PCG signals were tested in this study. The performance of automatic heart sounds localisation process is compared with that of manual measurements made by two experts. The results obtained are interesting especially for pathological cases heart sound.