Time Reference Research Articles

Passive Ultrasound Localization Microscopy of Nanodroplet Vaporizations During Proton Irradiation

Superheated nanodroplets (NDs) were recently proposed for <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">in vivo</i> proton range verification, owing to their ability to vaporize into echogenic microbubbles (MBs) upon exposure to ionizing radiation. In a previous publication, vaporization events were detected with 2D Ultrasound Localization Microscopy (ULM) based on a pulse-echo method. Here, we introduce P-ULM, a passive version of ULM, based on the detection of acoustic signatures emitted by vaporizing NDs, without actively transmitting ultrasound. Due to the lack of a time reference for the trigger of the ND vaporization, the time differences of arrival to each transducer element are used to retrieve the position of vaporizing NDs. P-ULM, compared to ULM, can continuously detect and super-localize sparse radiation-induced vaporization events with inherent specificity against already existing microbubbles, which otherwise would hinder range verification in the presence of vascular flow. We evaluated the localization performances of both methods theoretically and experimentally, by interleaving active and passive acquisitions on ND-phantoms irradiated with protons. P-ULM offered a higher sensitivity to vaporizations, as it detected twice as many events as ULM. Both methods retrieved, in the acoustic lateral direction, the proton range and range dispersion with sub-millimeter accuracy. In the acoustic axial direction, despite a degraded theoretical resolution limit, P-ULM retrieved the proton spot size with an accuracy similar to ULM. Importantly, P-ULM detected vaporization events with high specificity in the presence of flowing MBs, which makes the technique a candidate for in vivo proton range verification in the presence of flow.

DTW 기반 추진 전동기 잔여수명 예측 알고리즘 개발 사례연구

Recently, more detailed fault diagnosis is being performed by analyzing the current status and changes of equipment through condition monitoring data obtained through various sensor data. In addition to fault diagnosis, attempts to predict the remaining useful life (RUL) in the event of a fault are being studied in various ways. RUL prediction is very important as a key indicator that can be used as a reference for equipment replacement time, cost reduction, and accident prevention. In this study, we propose a method for predicting the remaining life of equipment by extracting an abnormal pattern based on data collected from a ship

DEVELOPMENT OF OFFICIAL INDONESIA STANDARD TIME : TEMPERATURE CONTROL SYSTEM FOR CAESIUM ATOMIC CLOCK

Every country should have an official time standard which called local coordinated universal time, UTC(k). Badan Standardisasi Nasional (BSN) has developed an official standard time, namely UTC(IDN) which is used as Indonesia Standard Time. The UTC(IDN) contributes to calculation of coordinated universal time (UTC). In order to generate the UTC(IDN), the output of 1 pulse per second signal of caesium atomic clock is utilized as the actual signals of this standard. A distribution amplifier is used to distribute the signal. Combination of time transfer system (TTS-3) and GPS are employed for comparison of UTC and UTC(IDN). TTS-3 automatically calculated the difference and it is steered by using certain algorithm. Time synchronization to the standard can be conducted through network time protocol (NTP) server, i.e., ntp.bsn.go.id. The time can be automatically synchronized using internet time or certain program at each computer or machine. The results of this work show that the time differences between UTC – UTC(IDN) vary from 43.2 ns to 1729.9 ns. UTC(IDN) has frequency and time stability of 3.6 x 10 -14 Hz/Hz per 5 days and 3.1 ns per 5 days, respectively which are in good agreement to the international time reference. A shielding chamber with temperature control system has been built to keep the ambient temperature of caesium atomic clock at (23 ± 1) ᵒC. It can be concluded that BSN has been developing and disseminating the UTC(IDN) as an Indonesia Standard Time that can support the regulation of time synchronization in Indonesia. A new temperature control system is proposed to stabilize the ambient temperature of caesium atomic clock. The temperature control system supports an accurate and stable UTC(IDN).

Sub-GHz Frequency Response of Anomalous Nernst Effect in the NiFe Block with Sinusoidal Laser Pulses

Because the anomalous Nernst effect (ANE) involves the effective electric field generated by the combination between the thermal gradient and the magnetization direction, it has been well applied to not only the measurement of the static magnetization but also the experiment for the low frequency magnetization dynamics. In this work, the frequency response of the ANE was examined to provide two implications: First, as a method to separate Nernst effects from other signals in the homodyne or heterodyne method, and second, as a timing reference to the phase-sensitive magnetization dynamics. The intensity of 1550 nm laser power was modulated up to 2.4 GHz and successfully produced the equivalent speed of the ANE signals from the 10 nm Permalloy block on the sapphire substrate. The implications could be supported, when the detection system consists of well-designed radio frequency components and the better heat sink substrate to get the faster thermal gradient on the magnets.

Signal generator based finite-time formation control for disturbed heterogeneous multi-agent systems

This paper investigates finite-time formation control problems of heterogeneous multi-agent systems subject to mismatched and matched disturbances. The studied agents are modelled with both different orders and dimensions. To achieve the desired finite-time formation control goal, a novel signal generator based finite-time formation control scheme is proposed, which is composed of two parts. In the first part, a distributed finite-time signal generator is established to produce formation references for the agents in finite time. In the second part, based on finite-time observer technique and homogeneous systems theory, a kind of composite anti-disturbance controllers are constructed for the agents to track the formation references in finite time. In this way, the studied multi-agent system completes the desired finite-time formation control task. Compared with the existing results, the proposed control scheme solves the disturbed finite-time formation control problems with both different agents’ orders and dimensions, simplifies the formation controller design by using a modular design philosophy, and makes the agents have a plug and play feature. A simulation example is shown to validate the effectiveness of the proposed control scheme.

Now or never? Temporal framing in risk messages and the moderating effect of comparative optimism

Risk messages inform consumers about relevant risks and typically recommend preventive behaviors such as being more physically active or taking out occupational disability insurance. Often, the appeals include some form of time reference, such as “find out about disability insurance this month” or “find out about disability insurance this year”. In general, the effects of such proximal compared to distal time references on compliance intention may be positive or negative, and we examine how the effects depend on consumers’ comparative optimism. In two studies in the context of occupational disability insurance, proximal temporal framing proved more effective than distal framing among comparative optimists but not among nonoptimists. We recommend that when targeting comparative optimists, risk message designers should use proximal temporal framing in their recommendations.

Towards optimizing the measurement of self‐perceived cognitive functioning: Examination of harmonized subjective cognitive items

AbstractBackgroundFor the item analysis project of the Subjective Cognitive Decline Initiative (SCD‐I) Working Group, we have pooled item level data from North American, European, and Australian cognitive aging studies. As a step toward developing a questionnaire that can be used across settings and studies, we examined similarly worded groups of items and compared their psychometric quality.MethodItem‐level subjective cognitive data were combined from 21 studies (&gt;18,000 participants). Unidimensional models consistent with item response theory captured a general subjective cognition factor using ADNI as the reference sample. Other studies were calibrated by using parameter constraints on common items. We characterized the measurement properties of 648 items from 35 measures utilized in the contributing studies. Next, we identified 20 groups of items (median items per group=6) with overlapping content from our previous study (Rabin et al., 2015), and plotted their item information curves, reflecting the items’ ability to discriminate between trait scores at different levels of the subjective cognition factor score. We then considered items with the highest peak information across groupings and identified commonalities in key features such as terminology of item stems, temporal referents, and response options.ResultWe present instrument characteristics (Table 1) and item information curves for 6 groupings (Figure 1). For items with the greatest information, we observed trends for the following features: clarity and directness of language of stem, utilization of current as opposed to other time referents, assessment of ability/level of difficulty rather than change over time or frequency of problem (Table 2).ConclusionWe identified key linguistic/structural features of subjective cognitive functioning items with the greatest contributions to measurement precision. We next plan to analyze all item groupings in our test bank to facilitate construction of a measure with high quality items from cognitive domains of interest (e.g., memory, language, executive functioning). Ultimately, we hope to derive a subjective cognitive screening tool that enables reliable identification of subtle cognitive changes in clinically normal individuals.

Metabolites and metabolic pathways of maackiain in rats based on UPLC-Q-TOF-MS

Ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry(UPLC-Q-TOF-MS) was used to investigate the metabolites of maackiain in rats based on the prediction function of UNIFI data processing system and liver microsomal incubation in vitro. Ten metabolites of maackiain after oral absorption were reasonably deduced and characterized. It was found that the biotransformation of maackiain mainly included phase Ⅰ oxidation, dehydrogenation, phase Ⅱ sulfate conjugation, glucosylation conjugation, and glucuronic acid conjugation. Among them, the product of glucosylation conjugation, trifolirhizin, was identified by comparison with the reference for the first time. Liver microsomal incubation in vitro further confirmed the metabolites and metabolic pathways of maackiain in rats. The metabolites in the blood, urine, and feces complemented each other, which revealed the migration, metabolism, and excretion modes of maackiain in rats. This study lays a foundation for the further investigation of the metabolic mechanism of maackiain in vivo and the in-depth research on the mechanism of pharmacodynamics and toxicity.

Active participles in Jordanian Arabic

Abstract This study examines the categorial status, syntactic derivation, and tense of active participles in an urban variety of Jordanian Arabic. It is shown that unlike in other Arabic varieties, active participles in Jordanian Arabic fall into three distinct categories (namely, nominal, adjectival, and verbal) with respect to their morphophonological, syntactic and semantic structures. Moreover, it is argued that active participles are not lexically underspecified or homophonous, but are rather derived distinctively in the syntax. This study also explores tense in active participle clauses. Verbless clauses with adjectival and nominal active participles as the only predicates solely project present tense; a past or future tense is available only if a copula is involved. In contrast, clauses with verbal active participles, which are morphologically unmarked for tense, are shown to license temporal adverbs of different time references. It is argued that such clauses project a covert agreement tense whose time frame is established by time adverbs.

Initial Results of Modeling and Improvement of BDS-2/GPS Broadcast Ephemeris Satellite Orbit Based on BP and PSO-BP Neural Networks

With the rapid development and gradual perfection of GNSS in recent years, improving the real-time service performance of GNSS has become a research hotspot. In GNSS single-point positioning, broadcast ephemeris is used to provide a space–time reference. However, the orbit parameters of broadcast ephemeris have meter-level errors, and no mathematical model can simulate the variation of this, which restricts the real-time positioning accuracy of GNSS. Based on this research background, this paper uses a BP (Back Propagation) neural network and a PSO (Particle Swarm Optimization)–BP neural network to model the variation in the orbit error of GPS and BDS broadcast ephemeris to improve the accuracy of broadcast ephemeris. The experimental results showed that the two neural network models in GPS can model the broadcast ephemeris orbit errors, and the results of the two models were roughly the same. The one-day and three-day improvement rates of RMS(3D) were 30–50%, but the PSO–BP neural network model was better able to model the trend of errors and effectively improve the broadcast ephemeris orbit accuracy. In BDS, both of the neural network models were able to model the broadcast ephemeris orbit errors; however, the PSO–BP neural network model results were better than those of the BP neural network. In the GEO satellite outcome of the PSO–BP neural network, the STD and RMS of the orbit error in three directions were reduced by 20–70%, with a 20–30% improvement over the BP neural network results. The IGSO satellite results showed that the PSO–BP neural network model output accuracy of the along- and radial-track directions experienced a 70–80% improvement in one and three days. The one- and three-day RMS(3D) of the MEO satellites showed that the PSO–BP neural network has a greater ability to resist gross errors than that of the BP neural network for modeling the changing trend of the broadcast ephemeris orbit errors. These results demonstrate that using neural networks to model the orbit error of broadcast ephemeris is of great significance to improving the orbit accuracy of broadcast ephemeris.

Effect of Joule heating on the performance of micromechanical piezoresistive oscillator

Joule heating is more widely existed in micromechanical resonators, and is also an innovative approach for the implementation of mechanical resonator in a broad range of fields such as timing applications, filters and sensors. However, the physical mechanism by which Joule heating affects the performance of resonator has not been thoroughly studied, and the ability to accurately control heat and suppress thermal noise in micro-and nanomechanical resonators remains a key challenge limiting practical applications as well. In this paper, we established the theoretical model based on temperature variation to explain the physical mechanism of the Joule heating effect on the performance of resonator. In the experiment, when the drain current increased from 3.35 mA to 11.62 mA, the dynamic range enhanced by 20.3 dB, which verified that the drain current can be conducive to enhance the signal-to-noise ratio (SNR) of resonator. Intuitively, adding Joule heating will make more thermal noise for the system, which will deteriorate the frequency stability of oscillator. However, there was a counterintuitive phenomenon in piezoresistive oscillator. Contrary to the capacitive oscillator, for a self-sustained mechanical oscillator based on piezoresistive detection method, the frequency stability of oscillator will be improved as the drain current increases. The experimental result showed that the Allan deviation have improved with a slope of −11.22ppb/mA. Our finding revealed the potential of joule heating for applications in high dynamic range sensors and time reference oscillators, as well as the fundamental study of the temperature variation and energy dissipation in micro and nano systems.

Is language priced? evidence from bank loan contracting

ABSTRACT Previous studies document that firms in countries speaking languages with strong future time reference (FTR), which more sharply dissociates the future from the present, engage in less future-oriented corporate behaviors relating to their default and information risks. We find that strong FTR influences creditors’ pricing of bank loan contracts: banks design more unfavorable loan terms to strong-FTR borrowers, including larger loan spread, higher likelihood of collateral requirement, and more covenants. This effect can be mitigated by a country’s strong governance. We confirm that strong FTR is associated with higher default and information risks of borrowing firms. Overall, our findings suggest that language represents a distinctive risk to banks which is priced in the loan market.

Qualitative dynamics of waxy maize (Jikenuo 19) in different harvest times

Jikenuo 19 was used as experimental material, and six harvest times were set to study the effects of different harvest times on grain quality and gelatinization characteristics, so as to provide reference for the harvest time and quality improvement of waxy maize varieties. The results showed that when the harvest time was 27 days after pollination, the sensory and cooking quality score of Jikenuo 19 was the highest. Starch content increased with the delay of harvest time, while protein and soluble sugar content decreased. With the delay of harvest time, the peak viscosity, valley viscosity, final viscosity, disintegration value, recovery value and peak time all showed a trend of first increasing and then decreasing. Compared with starch and soluble sugar, the effect of protein in grain on gelatinization characteristics was higher. The present findings reveal that the best harvest time was 27 days after pollination, which will provide reference for determining the best harvest time and improving grain quality. Bangladesh J. Bot. 50(3): 987-992, 2021 (September) Special

A lithium laser-ablation based time-of-flight (LILA-TOF) diagnostic for measuring plasma edge ion temperature and toroidal plasma rotation

A new method for studying the thermalization and transport of injected impurities at the edge of hot plasma, (considering the last closed magnetic surface, the free path is between 1 and 2 cm approx.) under no perturbative conditions, is presented. In the proposed technique, a Nd:YAG laser is used to ablate Li from the lithiated wall of the stellarator TJ-II. While the laser pulse allows for the analysis of the released species through laser induced breakdown spectroscopy (LIBS), its laser pulse also provides a time reference for the time-of-flight (TOF) measurements of the Li+ ions performed. This is done by positioning light detection systems sensitive to an intense Li II spectral line at different toroidal locations away from such a source. TOF times of tens to hundreds of microseconds are recorded. Then, by de-convolving the shape of the recorded light pulse, the velocity distribution of the lithium-ion during its thermalization with the background plasma can be extracted. From this velocity distribution, the ion temperature of the background ions and the toroidal rotation at the plasma periphery can be deduced. In contrast with conventional Doppler spectroscopy, this technique uses filter-scope detectors rather than high-spectral-resolution spectrometers thus a tradeoff between spectral and time or space resolution is required. Finally, preliminary results of the application of this novel technique are shown to validate this proof of principle.

Languages, M&amp;A Risks and Earnouts: A Global Perspective

Users of strong future time reference (FTR) languages(e.g., English) are grammatically required to distinguish between future and present events, while users of weak FTR languages (e.g., Chinese) are not. This study hypothesizes that firms using weak FTR languages as working languages are prone to believing that negative events(e.g., moral hazards) inM&amp;A transactions are more imminent and therefore have a higher degree of motivation to hedge against M&amp;A risks. Consistent with the baseline hypothesis, I find evidence that buyers with weak FTRlanguages as their working languages have a higher probability to use earnouts in M&amp;A transactions to hedge against investment risks. Next, I conduct robustness checks by altering samples. I also find that the extent of trade globalization has a negative mediating effect on the FTR-earnout mechanism. This study provides a new perspective to study the factors affecting the usage of earnouts in M&amp;A transactions and enriches the literature in linguistics.

The effect of language on financial inclusion

This study explores whether cross-country differences in financial inclusion can partly be attributed to language heterogeneity. We examine if the future time reference (FTR) component of a language affects intertemporal decision making of individuals when it comes to financial inclusion. We analyze this premise in the backdrop of the extant literature which demonstrates that speakers of languages that demonstrate weak-FTR tend to give relatively more importance to the future. Based on a sample of 78 countries and employing OLS, probit, and instrumental variable methods, we demonstrate that countries where the dominant language exhibits weak-FTR, the percentage of population making use of various financial services, is relatively higher. Further, we identify patience, educational attainment, and tax morale, as potential channels through which the weak-FTR component of language might impact financial inclusion. Our results are robust to controlling for cross-country and individual-level characteristics, language evolution, and alternate future marking behavioral indicators.

Automation Design of Kentongan Sound for The Feeding Process of Vaname Shrimp Farming in Pond

Feeding on vanamei shrimp culture in pondsis carried out on average 4 to 5 times a day. In aquaculture activities with a large number of ponds, the sound of kentongan becomes a time reference for the operator in providing feed. The purpose of this article was to describe the process required to turn the kentongan sound into a command input for an automatic feeder. The sound of kentongan will be used as input data (commands) for the microcontroller is translated as a command for the feeder to carry out its activities of feeding. The methodology used the following points: first, field observations of the use of kentongan sounds as a sign of the feeding process for feed operators; second, literature study covering sound frequency and sensor system; third, the creation of a chart in the form of step by step logic from input in the form of kentongan sounds to the process of feeding using an automatic feeding device; fourth, the design of the hardware that will be used and the creation of the software in the form of a command flow chart. The result was realized in the form of a chart from input in the form of kentongan sounds to the process of feeding using an automatic feeder. This includes hardware and software design. There were two important things in automation design. The identification process of kentongan sounds becomes a function of frequency against time, where this frequency had certain characteristics which were expressed by graphs that have certain equation values. This kentongan sound with a certain frequency will be the input for the microcontroller to carry out its task of giving orders to the feeding device to provide feed for vanamei shrimp in ponds.

MECCA MEAN TIME PROBLEMATIC AS A WORLD TIME REFERENCE

Desire of Muslims to replace the present standard of time, namely Greenwich Mean Time, to Mecca Mean Time is the manifestation of a new spirit in the Islamic world in particular. Mecca Mean Time makes al-Abraj tower (Mecca Royal Clock) the zero degree point or standard for the commencement of global time. The goal of this study is to find out what are the challenges that occur when Mecca Mean Time is used as a reference for global time. This research is a sort of qualitative research involving library research studies by describing descriptively. After the data is obtained, the author will categorize, analyze and present it in the form of a brief and systematic document. In this study, it was revealed that there was a debate of variations in views amongst different specialists when MMT was utilized as a reference for global time. Bambang Eko Budhiyono is striving very hard to achieve MMT as a world time reference on the basis of interpretation of the Qur'an verse 1 al-Hujurat. Meanwhile, Thomas Djamaluddin has a different perspective since physically and geographically there are no qualities that assist it to make it a time reference or as a main meridian (Prime Meridian) except religious spirit.

An Innovative Copula in Maghrebi Arabic and Its Dialectological Repercussions: The Case of Copular yabda

Research on copulas in Arabic dialects has hitherto largely focused on the pronominal copula, and has also mostly ignored Maghrebi dialects. Drawing on published literature as well as fieldwork-based corpora, this article identifies and analyzes a hitherto undescribed verbal copula in dialects of Tunisian and northwestern Libya deriving from the verb yabda (“to begin”). We show that copular yabda occurs mostly in predicational copular sentences, with time reference including the habitual present and generic future. It takes nominal, adjectival, and locational predicate types. We also argue for broader inclusion of syntactic isoglosses in Arabic dialectology, and show how copular yabda crosses the traditional isogloss lines established on the basis of phonology, morphology, or lexicon, and therefore contradicts established dialect classifications such as Bedouin/sedentary or Tunisian/Libyan.

Space time clock: An on-chip clock with 10−12 instability

High precision and stable clock is extremely important in communication and navigation. The miniaturization of the clocks is considered to be the trend to satisfy the demand for 5G and the next generation communications. Based on the concept of meter bar and the principle of the constancy of light velocity, we designed a micro clock, Space Time Clock (STC), with the size smaller than 1 mm × 1 mm and the power dissipation less than 2 mW. Designed in integrated circuit of 0.18 μm technology, the instability of STC is assessed to be 2.23 × 10−12 and the trend of the instability is reversely proportional to τ. With the potential ability to reach the level of 10−16 instability on chip in the future, the period of the STC’s signal is locked on the delay time defined by the meter bar which keeps the time reference constant. Because of its superior performance, the STC is more suitable for mobile communication, PNT (Positioning, Navigation and Timing), embedded processor and deep space application, and becomes the main payload of the ASRTU satellite scheduled to launch next year and investigate in space environment.