Precise Timing Information Research Articles

Evaluating Temporal Analysis Methods Using Residential Burglary Data

Law enforcement agencies, as well as researchers rely on temporal analysis methods in many crime analyses, e.g., spatio-temporal analyses. A number of temporal analysis methods are being used, but a structured comparison in different configurations is yet to be done. This study aims to fill this research gap by comparing the accuracy of five existing, and one novel, temporal analysis methods in approximating offense times for residential burglaries that often lack precise time information. The temporal analysis methods are evaluated in eight different configurations with varying temporal resolution, as well as the amount of data (number of crimes) available during analysis. A dataset of all Swedish residential burglaries reported between 2010 and 2014 is used (N = 103,029). From that dataset, a subset of burglaries with known precise offense times is used for evaluation. The accuracy of the temporal analysis methods in approximating the distribution of burglaries with known precise offense times is investigated. The aoristic and the novel aoristic e x t method perform significantly better than three of the traditional methods. Experiments show that the novel aoristic e x t method was most suitable for estimating crime frequencies in the day-of-the-year temporal resolution when reduced numbers of crimes were available during analysis. In the other configurations investigated, the aoristic method showed the best results. The results also show the potential from temporal analysis methods in approximating the temporal distributions of residential burglaries in situations when limited data are available.

Scintillating fiber detectors for precise time and position measurements read out with Si-PMs

We present the development and performance of compact scintillating fiber detectors read out with silicon photo-multipliers (Si-PMs). The compact size, fast response, and insensitivity to magnetic fields make these detectors suitable for a variety of applications where precise tracking and timing information is required. These detectors will be used with different particle beams (electrons, protons, heavy ions) at very high rates. In particular, we present the SciFi tracker/time of flight detector that is being developed for the Mu3e experiment at PSI (search for the lepton flavor violating decay μ→eee at very high rates). We also present the SciFi beam position detectors that will be employed in NA61 at CERN to track the incoming proton and heavy ion beam particles. We are considering different readout scenarios in which (a) each fiber is individually coupled to a single Si-PM photo-sensor and (b) fibers are arranged in columns and coupled to a Si-PM arrays.

Speed Adaptation in Urban Road Network Management

Abstract Various forecasting schemes have been proposed to manage traffic data, which is collected by videos cameras, sensors, and mobile phone services. However, these are not sufficient for collecting data because of their limited coverage and high costs for installation and maintenance. To overcome the limitations of these tools, we introduce a hybrid scheme based on intelligent transportation system (ITS) and global navigation satellite system (GNSS). Applying the GNSS to calculate travel time has proven efficient in terms of accuracy. In this case, GNSS data is managed to reduce traffic congestion and road accidents. This paper introduces a short-time forecasting model based on real-time travel time for urban heterogeneous road networks. Travel time forecasting has been achieved by predicting travel speeds using an optimized exponential moving Average (EMA) model. Furthermore for speed adaptation in heterogeneous road networks, it is necessary to introduce asuitable control strategy for longitude, based on the GNSS. GNSS products provide worldwide and real-time services using precise timing information and, positioning technologies.

Randomised testing of a microprocessor model using SMT-solver state generation

We validate a HOL4 model of the ARM Cortex-M0 microcontroller core by testing the model's behaviour on randomly chosen instructions against real chips from several manufacturers.The model and our intended application involve precise timing information about instruction execution, but the implementations are pipelined, so checking the behaviour of single instructions would not give us sufficient confidence in the model. Thus we test the model using sequences of randomly chosen instructions.The main challenge is to meet the constraints on the initial and intermediate execution states: we must ensure that memory accesses are in range and that we respect restrictions on the instructions. By careful transformation of these constraints an off-the-shelf SMT solver can be used to find suitable states for executing test sequences. We also use additional constraints to test our hypotheses about the timing anomalies encountered.

HFirst: A Temporal Approach to Object Recognition.

This paper introduces a spiking hierarchical model for object recognition which utilizes the precise timing information inherently present in the output of biologically inspired asynchronous address event representation (AER) vision sensors. The asynchronous nature of these systems frees computation and communication from the rigid predetermined timing enforced by system clocks in conventional systems. Freedom from rigid timing constraints opens the possibility of using true timing to our advantage in computation. We show not only how timing can be used in object recognition, but also how it can in fact simplify computation. Specifically, we rely on a simple temporal-winner-take-all rather than more computationally intensive synchronous operations typically used in biologically inspired neural networks for object recognition. This approach to visual computation represents a major paradigm shift from conventional clocked systems and can find application in other sensory modalities and computational tasks. We showcase effectiveness of the approach by achieving the highest reported accuracy to date (97.5% ± 3.5%) for a previously published four class card pip recognition task and an accuracy of 84.9% ± 1.9% for a new more difficult 36 class character recognition task.

Angle sensitive single photon avalanche diode

An ideal light sensor would provide exact information on intensity, timing, location, and angle of incoming photons. Single photon avalanche diodes (SPADs) provide such desired high (single photon) sensitivity with precise time information and can be implemented at a pixel-scale to form an array to extract spatial information. Furthermore, recent work has demonstrated photodiode-based structures (combined with micro-lenses or diffraction gratings) that are capable of encoding both spatial and angular information of incident light. In this letter, we describe the implementation of such a grating structure on SPADs to realize a pixel-scale angle-sensitive single photon avalanche diode (A-SPAD) built in a standard CMOS process. While the underlying SPAD structure provides high sensitivity, the time information of the two layers of diffraction gratings above offers angle-sensitivity. Such a unique combination of SPAD and diffraction gratings expands the sensing dimensions to pave a path towards lens-less 3-D imaging and light-field time-of-flight imaging.

New Aspects for the Hierarchical Cooperative Motions in Photoalignment Process of Liquid Crystalline Block Copolymer Films

The realignment process of azobenzene-containing liquid crystalline (LC) block copolymer films by irradiation with linearly polarized light (LPL) was investigated in detail by time-resolved grazing incidence X-ray scattering measurements using a synchrotron beam. By using a newly synthesized diblock copolymer possessing a poly(hexyl methacrylate (PHMA) block with a lowered glass transition temperature (Tg = −5 °C), intense X-ray scattering signals were obtained, which favorably provided precise and detailed time course profiles and information on the interplay between the hierarchical structures involved along the realignment process. The LC layers were softened and fluctuated at an early stage by LPL irradiation which induced shrinkage of the cylinder to cylinder distance of microphase separation patterns before the alignment change. Interestingly, the ordering process of the MPS cylinder array of larger hierarchical structure proceeded faster than that of the azobenzene LC layer of smaller feature size in the realigned state. Decisive evidence was obtained to support the subdomain rotation mechanism in the realignment process.

Application of the time-delay integration method: Survey observations of geosynchronous orbit objects and short-term variability observations

Abstract “Time-Delay Integration (TDI)” readout technique has been adopted to a mosaic CCD camera equipped with four fully-depleted CCDs. Optical distortion and image deformation due to the TDI operation are discussed. The manner and advantages of the TDI method in survey observations of geosynchronous orbit objects are summarized. We propose a new TDI application method of getting short-term light curves of artificial space objects. This method of detecting a short-term variability can be applied for a variety of objects, ranging from satellites to stars. It can also be used for the light-curve observations of transient objects which might show short-term variability and of which the precise time information is needed.

DEVELOPMENT OF FOOD SECURITY INFORMATION SYSTEM BASED ON BUSINESS INTELLIGENCE IN FOOD SECURITY AGENCY, MINISTRY OF AGRICULTURE, INDONESIA

Food is the main basic need of human, because of that fulfillment of human need of food has to be fulfilled. So it can fulfill that need, then government institution, Food Security Agency (BKP) is formed so it can monitor fulfillment of food need of society. The goals of this writing are to develop food security information system that provides dashboard facility based on business intelligence, to develop food security information system that can give fast, precise and real time information about food security, to develop decision-making support system for chairman in food security institution. Data is obtained from questionnaires to 51 respondents that are chairmen in Food Security Agency. Data is analyzed with SWOT analysis method for business environment and IT balanced scorecard (IT BSC) for IS/IT environment. The result of analysis of food security information system in Food Security Agency can help chairman in decision-making by presenting information about dashboard that gives fast, precise and real time information. It can be concluded that development of information is successfully done.

A method for the joint inversion of geodetic and seismic waveform data using ABIC: application to the 1997 Manyi, Tibet, earthquake

Geodetic imaging data and seismicwaveformdata have complementary strengthswhen considering the modelling of earthquakes. The former, particularly modern space geodetic techniques such as Interferometric Synthetic Aperture Radar (InSAR), permit high spatial density of observation and thus fine resolution of the spatial pattern of fault slip; the latter provide precise and accurate timing information, and thus the ability to resolve how that fault slip varies over time. In order to harness these complementary strengths, we propose a method through which the two data types can be combined in a joint inverse model for the evolution of slip on a specified fault geometry. We present here a derivation of Akaike's Bayesian Information Criterion (ABIC) for the joint inversion of multiple data sets that explicitly deals with the problem of objectively estimating the relative weighting between data sets, as well as the optimal influence of model smoothness constraints in space and time. We demonstrate our ABIC inversion scheme by inverting InSAR displacements and teleseismic waveform data for the 1997 Manyi, Tibet, earthquake.We test, using a simplified fault geometry, three cases-InSAR data inverted alone, vertical component teleseismic broad-band waveform data inverted alone and a joint inversion of both data sets. The InSAR-only model and seismic-only model differ significantly in the distribution of slip on the fault plane that they predict. The joint-inversion model, however, has not only a similar distribution of slip and fit to the InSAR data in the InSAR-only model, suggesting that those data provide the stronger control on the pattern of slip, but is also able to fit the seismic data at a minimal degradation of fit when compared with the seismic-only model. The rupture history of the preferred, joint-inversion model, indicates bilateral rupture for the first 20 s of the earthquake, followed by a further 25 s of westward unilateral rupture afterwards, with slip peaking at 7m in the upper 6 km of the fault. This joint-inversion approach is thus shown to be a viable method for the study of large shallow continental earthquakes, and may be of particular benefit in cases where near-field seismic observations are not available. © The Authors 2014. Published by Oxford University Press on behalf of The Royal Astronomical Society.

Timing Measurement Platform for Arbitrary Black-Box Circuits Based on Transition Probability

The key aspects of a good on-chip timing measurement platform are high measurement resolution, accuracy, and low area overhead. A measurement method based on transition probability (TP) has shown promising characteristics in all these areas. In this paper, the TP measurement method is examined through simulation to understand its apparent effectiveness and accuracy in measuring complex circuits. Timing uncertainties and logic glitch activities are considered in detail, and the effect of varying input vectors' probability distributions is analyzed to enable further accuracy improvements. Using a field-programmable gate array, the method is implemented and demonstrated as a modular on-chip test platform for testing complex arbitrary circuits. Practical circuits found in typical modular designs, including fixed/floating-point arithmetic and filter circuits, are chosen to evaluate the test platform. The resolution of the timing measurements ranges from 0.3 to 8.0 ps, and the measurement errors against reference measurements are found to be within 3.6%. The test platform can be applied to VLSI designs with minor area overhead, and provides designers with precise and accurate physical timing information of circuits.

In situ monitoring of dynamic bounce phenomena in RF MEMS switches

This paper presents the first ultra-low-power complementary metal–oxide–semiconductor (CMOS)-based measurement technique for monitoring the cold-switched dynamic behavior of ohmic radiofrequency microelectromechanical systems (RF MEMS) switches in real time. The circuit is capable of providing precise information about contact timing and ohmic contact events. Sampling of dynamic events at frequencies of 1 and 5 MHz shows contact timing accuracy of 99% when compared with real-time true-height information obtained from laser Doppler vibration data. The technique is validated for an ohmic RF MEMS switch with multiple bounces. The actuation voltage has also been designed to enhance bouncing behavior to more clearly study the performance and limits of the presented technique. More than 13 bounces are successfully captured by the electronic measurement technique. The weakest bounces exhibit vertical displacements of less than 20 nm as recorded by a laser Doppler vibrometer. This demonstrates the ability to capture precise timing information even for weak contacting events. A detailed discussion of how parasitics influence this technique is also presented for the first time.

Describing disease processes using a probabilistic logic of qualitative time

Clinical knowledge about progress of diseases is characterised by temporal information as well as uncertainty. However, precise timing information is often unavailable in medicine. In previous research this problem has been tackled using Allen's qualitative algebra of time, which, despite successful medical application, does not deal with the associated uncertainty. It is investigated whether and how Allen's temporal algebra can be extended to handle uncertainty to better fit available knowledge and data of disease processes. To bridge the gap between probability theory and qualitative time reasoning, methods from probabilistic logic are explored. The relation between the probabilistic logic representation and dynamic Bayesian networks is analysed. By studying a typical, and clinically relevant problem, the detection of exacerbations of chronic obstructive pulmonary disease (COPD), it is determined whether the developed probabilistic logic of qualitative time is medically useful. The probabilistic logic extension of Allen's temporal algebra, called Qualitative Time CP-logic provides a tool to model disease processes at a natural level of abstraction and is sufficiently powerful to reason with imprecise, uncertain knowledge. The representation of the COPD disease process gives evidence that the framework can be applied functionally to a clinical problem. The combination of qualitative time and probabilistic logic offers a useful framework for modelling knowledge and data to describe disease processes in clinical medicine.

Optimization of the global network of tracking stations to provide GLONASS users with precision navigation and timing service

The requirements for the topology of the global network of tracking stations have been analyzed. The methodology for developing a network has been proposed; experimental research has been conducted to study the potential of the global network to supply GLONASS users with precision navigation and time information. The lines of the development of GLONASS measuring technologies are considered.

Silicon vertex detector upgrade in the ALPHA experiment

The Silicon Vertex Detector (SVD) is the main diagnostic tool in the ALPHA-experiment. It provides precise spatial and timing information of antiproton (antihydrogen) annihilation events (vertices), and most importantly, the SVD is capable of directly identifying and analysing single annihilation events, thereby forming the basis of ALPHA's analysis. This paper describes the ALPHA SVD and its upgrade, installed in the ALPHA's new neutral atom trap.

Time Synchronization Attack in Smart Grid: Impact and Analysis

Many operations in power grids, such as fault detection and event location estimation, depend on precise timing information. In this paper, a novel Time Synchronization Attack (TSA) is proposed to attack the timing information in smart grid. Since many applications in smart grid utilize synchronous measurements and most of the measurement devices are equipped with global positioning system (GPS) for precise timing, it is highly probable to attack the measurement system by spoofing the GPS. The effectiveness of TSA is demonstrated for three applications of phasor measurement unit (PMU) in smart grid, namely transmission line fault detection, voltage stability monitoring and event locationing. The validity of TSA is demonstrated by numerical simulations.

Analysis of GNSS Interference Impact on Society and Evaluation of Spectrum Protection Strategies

Global Navigation Satellite System (GNSS) technology is growing fast in our society and new applications are being introduced at an unprecedented pace. The GNSS products provide worldwide and real-time services using precise timing information, positioning and synchronization technologies. Within years, GNSS applications are becoming more accurate and their precision opens doors to a wide range of applications. Nevertheless, these applications are susceptible to disruption in the operation of GNSS receivers when malfunctions, failures or interference occur. This paper’s objective is to make an overall analysis of GNSS failure impact on society and therefore make a review of GNSS spectrum protection strategies. In the first three sections of this analysis, we survey GNSS applications, their importance and their criticality. While questioning the criticality of GNSS applications, we evaluate their impact on main critical infrastructures and particularly the risks of critical dependencies in case of failure or interference. In the last two sections, we investigate GNSS spectrum interference in relation to its effects on crucial infrastructures. We review the principal Radio Frequency Interference (RFI) sources leading to GNSS and satellite communications (SATCOM) spectrum issues. Alongside, we study various ways to mitigate RFI. This process is essential to further develop and standardize mitigation techniques and to ensure GNSS spectrum immunity against RFI.

Verification of Focusing System for Time-of-Propagation Counter

Abstract The results of verifying focusing system for Time Of Propagation (TOP) counter is presented. The TOP counter have been developed as a new detector for particle identification at Belle-II experiment, which is a Ring Imaging Cherenkov counter with precise timing information. Performance of the TOP counter is directly depended on the time resolution for single photon detection. Propagated Cherenkov photons have group velocity related to wavelength. It generates fluctuation of propagation time approximately 53 ps/m. Chromatic dispersion provides serious deterioration of time resolution. Against this problem, the focusing mirror is planed to introduce. It focuses Cherenkov light to different channels of MCP-PMT by different wavelength, and so that the deterioration of time resolution is suppressed. We verified focusing mechanism using 120 GeV/ c π beam at CERN. Using a prototype TOP counter with the focusing mirror, we could confirm a work of focusing mechanism. The time resolution improved from 147 ps to 95 ps by using focusing mirror.

A prototype TOF PET detector module using a micro-channel plate photomultiplier tube with waveform sampling

We are exploring a large area flat panel micro-channel plate photomultiplier tube (MCP PMT) under development for an application to time-of-flight positron emission tomography (TOF PET). High speed waveform sampling with transmission-lines is adopted for reading out the signal with precise time and space information with a small number of low-power channels. As a demonstration of the concept, detector modules have been built using 2″×2″ Photonis Planacon MCP PMTs (XP85022) and prototype transmission-line (TL) boards. The signals from the MCP PMT through the transmission-lines are sampled by DRS4 evaluation boards running at 5 giga-samples per second (GS/s). The event information is extracted by processing the digitized waveforms. For experimental tests, a single 3×3×10 mm(3) LYSO crystal is optically coupled to each MCP PMT; the detector responses to 511 keV annihilation photon from a (22)Na source are measured using the data taken in coincidence mode. As a preliminary result, we obtain a position resolution of ∼2.8 mm (0.3 mm) (FWHM) along (perpendicular to) the transmission-line, ∼309 ps (FWHM) for coincidence time resolution, and ∼14% (FWHM) of energy resolution at 511 keV. This initial result gives a promise that the large area MCP PMT is applicable to TOF PET.

A review of RFID technology and its managerial applications in different industries

Radio frequency identification (RFID) is an emerging technology that is increasingly being used in supply chain management. RFID technology plays an important role in supporting logistics and supply chain processes because of their ability to identify, trace and track information throughout the supply chain. The technology can provide suppliers, manufacturers, distributors and retailers precise real time information about the products. This accurate knowledge of the inventory would result in lower labor cost, simplified business processes and improved supply chain efficiency. If properly used, it has the potential to cut ordering lead time and cost on inventory control, increase the accuracy of inventory information, help avoid stockouts and boost the number of inventory turns. In this paper, we provide an overview of the current state of RFID applications in different industries and its impact on business operations. We provide extensive literature survey and develop a framework for future research areas in this field.