Abstract: Even if the propagation time interval of a sync signal is not constant, an accurate correction parameter is calculated, so that a corrected time point synchronized with a main clock device is obtained. A main transmission time point storage part stores respective main transmission time points at which a main device has transmitted a plurality of main sync signals and which are measured using a main clock device. A subordinate reception time point storage part stores respective subordinate reception time points at which a subordinate device has received the plurality of main sync signals and which are measured using a subordinate clock device. A speed ratio calculation part calculates a speed ratio of a ticking time speed of the main clock device to a ticking time speed of the subordinate clock device, based on a main transmission mean time point being a mean of the main transmission time points and a subordinate reception mean time point being a mean of the subordinate reception time points.

Abstract: Aspects of the invention provide systems and methods for using ballast sensors to detect rock fall events in a vicinity of railway tracks or similar roadways or tracks. The ballast sensors are spaced apart from the tracks. Particular embodiments permit the use of signals from the ballast sensors to discriminate rock fall events from other types of events and to detect the hypocenter of a rock fall event.

Abstract: Embodiments for providing Doppler sounds are disclosed. In one embodiment, provided is an ultrasound system which may include: an ultrasound data acquiring unit configured to transmit ultrasound signals to a target object and receive ultrasound echo signals reflected therefrom, to acquire a plurality of ultrasound data associated with the target object, each of which having a synchronization (Sync) number uniquely assigned thereto; a storing unit to store the plurality of ultrasound data therein; an user input unit configured to allow a user to input a user instruction; and a processing unit coupled to the ultrasound data acquiring unit, the storing unit and the user input unit and configured to form a Doppler mode image having the Sync number based on the plurality of ultrasound data, the processing unit being further configured to extract ultrasound data with a Sync number corresponding to the user instruction from the storing unit, thereby forming the Doppler sound based on the extracted ultrasound data.

Abstract: Devices and methods for identifying an electrical device, and its state, in a network of electrical devices are disclosed. An energy monitoring device is programmed to identify an electrical device coupled to a power supply, and a state of the electrical device, from a change in successive measurements of the power supply. Algorithms for determining a load signature for an electrical device and its state are disclosed. A stored table of load signatures for states is used to identify devices, and states. Energy monitoring information is collected and presented to the user on a display, a remote display, or is transmitted over a network to a remote device such as a personal computer, personal digital assistant, an iPhone®, a cell phone, voice mail, email, or text message.

Abstract: Methods, apparatuses and systems are described for outputting unsynchronized physiological data. The methods may include receiving a plurality of data streams, each data stream representing a physiological parameter for a person. The methods may also include selecting an epoch. Once the epoch is selected, the methods may also include determining, for each of the plurality of data streams, an epochal or summary value to represent each of the physiological parameters for the person in the epoch. The methods may additionally include outputting the epochal values with an indication of the selected epoch.

Abstract: A network analyzer for measuring a group delay time, which is caused by a device under test to be measured, generates an excitation signal comprising two signals (xIn1(t),xIn2(t)) spaced by a frequency difference, excites the device with the excitation signal and measures a response signal comprising two signals (xOut1(t),xOut2(t)), which are respectively phase distorted by the device relative to the signals (xIn1(t),xIn2(t)) of the excitation signal. It determines the phase difference (??In) between the signals (xIn1(t),xIn2(t)) associated with the excitation signal and a phase difference (??Out) between the signals (xOut1(t), xOut2(t)) associated with the response signal. Finally, it calculates the group delay time from the phase difference (??In) of the signals (xIn1(t),xIn2(t)) associated with the excitation signal, the phase difference (??Out) of the signals (xOut1(t),xOut2(t) associated with the response signal and the frequency difference.

Abstract: A system for determining an operational state of a machine is provided. The system includes an implement position sensor configured to generate a position signal indicative of a position of an implement. The system further includes a pressure sensor configured to generate a pressure signal indicative of a pressure of a cylinder of the machine. The system also includes a controller communicably coupled to the implement position sensor and the pressure sensor. The controller is configured to receive the position signal and the pressure signal. The controller is further configured to determine a weight of a payload of the machine based on the received signals. Further, the controller is configured to determine a dig status of the machine based, at least in part, on a rate of change of the weight of the payload and the position of the implement.

Abstract: The invention relates a method for determining the time dating event of creation of an object made of a cellulose containing material and having on its surface areas with a coating and without coating, in which the results of measurements of the components of nuclear-magnetic resonance relaxation are used for determining the parameters of free induction signals and the density of protons in cellulose samples taken from the cellulose containing material surface layer with coated and uncoated areas, the value G of relative changes of the cellulose parameters are calculated using the formula: G=K2/K2+Pr2/Pr1, where: Pr1 and Pr2 is the density of protons in cellulose, on the area having no coating and the area with a coating, respectively, g/sm3106; K1 and K2 are the degrees of crystallinity of the cellulose, on the area having no coating and the area with a coating, respectively, specified by the formula: K=1-5(T2*Ad/T2* Ak), where: T2M and T2 is the relaxation time of the short and long components

Abstract: Techniques pertaining to analyzing power consumed by a processing unit in a mobile computing device caused by execution of certain modules are described herein. A power trace is generated that indicates an amount of power consumed by the processing unit over time, and the power trace is aligned with an execution log. Spikes are extracted from the power trace, and computing operations are performed over the spikes to acquire data pertaining to power consumed by the processing unit that are attributable to modules in the execution log.

Abstract: A system for monitoring at least one rotating element is provided. The system can include a first sensor substantially aligned with a first rotating element, the first sensor being configured to detect a first marker on the first rotating element and thereby provide a first signal; a second sensor substantially aligned with a second rotating element, the second sensor being configured to detect a second marker on the second rotating element and thereby provide a second signal; and a measurement system coupled with the first sensor and the second sensor, wherein the measurement system is configured to: evaluate a time delay between a detection time of the first signal and a detection time of the second signal.

Abstract: Various embodiments provide systems, computer program products and computer implemented methods. Some embodiments include a system for modeling a relationship between a test time and a defect rate for a systematic multivariate issue caused by at least one predictable component and a random component in a semiconductor testing environment, the multivariate issue causing failure of a semiconductor device, the system that includes at least one computing device configured to perform actions including quantifying the at least one predictable component to produce at least one first mathematical form, quantifying the random component using distribution functions to produce a second mathematical form and producing a mathematical model of a relationship between the test time and the defect rate at a test condition by mathematically combining the at least one first mathematical form and the second mathematical form.

Abstract: An image detection program creating system comprise a parameter setting module, an image loading module, a programming module, and a program conversion module. The parameter setting module sets parameters of a Dimensional Measuring Interface Specification (DMIS). The image loading module loads a 3D image. The programming module programs the DMIS program according to the parameters of the DMIS and the 3D image. The program conversion module converts the compiled DMIS into an image detection program.

Abstract: A device for calculating round-trip time of a memory test using a programmable logic includes a pattern generation part including two pairs of input/output (IO) pins to generate a pattern signal for testing, and receiving a feedback signal through bidirectional buses from IO lines; two pairs of bidirectional buses for relaying a signal between the pattern generation part and a programmable logic part; and a programmable logic part for transmitting the pattern signal to the IO lines through the bidirectional buses and transmitting the feedback signal to the bidirectional buses from the IO lines, and including a multiplexer for crossing a signal connection direction upon calculation of the feedback signal, wherein the pattern generation part measures an input time of the feedback signal based on an output time of the pattern signal, thus calculating the round-trip time of the signal.

Abstract: Systems and methods are provided that are capable of synchronizing an industrial process. The industrial process may include a plurality of process levels. A visualization group may be displayed, showing the various levels of a process. A transition group may be graphically defined that allows for the linking of the transitions between the various process levels. In certain embodiments, sequential function charts (SFC) may include expanded capabilities that allow for the visual definition, editing, and review of the transition groups. Such SFC embodiments may be capable of process flow synchronization across any levels of the modeled process.

Abstract: A method detects a threshold crossing instant at which a signal crosses a threshold, by: sampling the signal at plural sampling instants spaced from one another by a sampling period; detecting consecutive first and second sampling instants at which the signal has a first signal value lower than or equal to the threshold, and the signal has a second signal value higher than the threshold, respectively; calculating a first interval indicative of a time between the threshold crossing instant and the first sampling instant; setting a reference signal having a reference amplitude representing the first interval relative to a reference scale; generating a signal with a delay depending on said reference signal; generating a threshold crossing detection signal at an instant delayed by a second interval; calibrating the reference scale of the reference amplitude so that the second interval is substantially equal to the first interval.

Abstract: A method for recording pulse signals which allows the reconstruction of a time reference. The time of every pulse signal event can be determined by counting sampling result bits preceding the respective sampling result bit using the known sampling frequency. For this purpose, every period of the sampling frequency is associated with a bit representing the respective sampling result and the sampling result bits are stored one by one and per channel in data blocks. The sampling frequency is preferably higher than a pixel clock, a sampling result bit associated with a flank of the pixel clock being marked. The pixel clock can thus be synchronized with the individual events exactly per sampling period. The invention further relates to the field of fluorescence correlation spectroscopy using confocal microscopes or laser scanning microscopes.

Abstract: A life management circuit for managing usage rates of a plurality of electronic components includes a storage unit for storing usage information corresponding to each electronic component, a receiving unit, a determining unit and a control unit. Upon receipt of an activation command passed on thereto via the receiving unit, the control unit selects for activation, with reference to the usage information of the electronic components stored in the storage unit, at least one electronic component, the usage information corresponding to which reveals a usage rate that is comparatively lower among the electronic components, controls the determining unit to keep track of the duration of time that the selected at least one electronic component remains activated in response to the activation command, and updates the usage information corresponding to each of the selected at least one electronic component with reference to the duration of time tracked therefor.

Abstract: A method of analysing blade tip timing data obtained from an array (Pk) of stationary timing probes (3) that are spaced at integer multiples of a base angle. Replace one of the probes (3) with a virtual probe (Pv) to give a virtual probe set (42). Set an initial probe angle (?v) and an initial engine order (EOv) for the virtual probe (Pv). Calculate the condition number (CN) for the virtual probe set (42). If the condition number (CN) at least meets a threshold criterion, solve the virtual probe set (42) for blade tip displacement amplitude. Else increment the virtual probe angle (?v) and/or the virtual engine order and iterate from calculating the condition number. Else reinstate the replaced probe (3) and replace a different probe (3) from the array of probes (Pk) with the virtual probe (Pv); then iterate from setting the initial virtual probe angle and engine order.

Abstract: A method of detecting one or more blocked sampling holes in a pipe of an aspirated smoke detector system. The method includes ascertaining the base flow of fluid through a particle detector using a flow sensor; monitoring subsequent flow through the particle detector; comparing the subsequent flow with the base flow; and indicating a fault if the difference between the base flow and the subsequent flow exceeds a predetermined threshold.

Abstract: A display apparatus includes a display panel, a light source part, a light source driving part and a used time calculation part. The light source part includes a light source providing the display panel with lights. The light source driving part includes a boost part outputting a light source driving voltage and a light source driving chip controlling the boost part. The used time calculation part detects an initial drive time during which an initial driving voltage is supplied to the light source driving chip and a normal drive time during which a normal driving voltage is supplied to the light source driving chip, and calculates a used time of the light source by using the initial drive time and the normal drive time. Thus, a real used time of a light source may be provided to correctly estimate lifetime of a light source.

Abstract: A method of calculating a time difference is disclosed. The method includes receiving a first ultrasonic signal (r21) from a first transducer (UT1) and receiving a second ultrasonic signal (r12) from a second ultrasonic transducer (UT2). The first and second ultrasonic signals are sampled to produce respective first and second sampled ultrasonic signals (502). Points having a value greater than a first threshold are selected from the first and second sampled ultrasonic signals (510). A difference in travel time between the first and second ultrasonic signals is calculated (512) in response to the selected points.

Abstract: A timer unit includes a timer for timing the period of time the logic circuit has been in the self-test mode. A comparator is connected to the timer, for comparing the period of time with a maximum for the period of time the logic circuit is allowed to be in the self-test mode and outputting an error signal when the period of time exceeds the maximum. The test timer unit further includes a mode detector for detecting a switching of the logic circuit to the self-test mode. The mode detector is connected to the timer, for starting the timer upon the switching to the self-test mode and stopping the timer upon a switching of the logic circuit out of the self-test mode. The timer unit can be used in a system for testing a logic circuit which includes a test routine module containing a set of instructions which forms a test routine for performing a test on a tested part of the logic circuit.

Abstract: A hydraulic control system for operating a subsea blowout preventer includes a surface manifold configured to convey hydraulic power to the blowout preventer, a surface actuation valve hydraulically connected to subsea valves and configured to operate the blowout preventer, and a control system monitoring apparatus. The control system monitoring apparatus includes a surface manifold pressure transducer hydraulically connected to the surface manifold, an electronic readback system, and a surface control line pressure transducer hydraulically connected to the surface end of at least one control hose and the surface actuation valve. The control system monitoring apparatus is configured to read, record, and process pressure data supplied by the surface manifold and surface control line pressure transducers.

Abstract: A calculation method includes obtaining a temporal sequence of position data representing movement loci of an agricultural machine; extracting from among the obtained sequence of position data, a set of position data representing an interval among the movement loci of the agricultural machine and in which slopes of segments connecting two points represented by consecutive position data among the sequence of position data are consecutively within a given range; and calculating based on the extracted set of position data representing the interval, a length of a work interval of agricultural work performed by the agricultural machine. The calculation method is executed by a computer.

Abstract: Systems and methods relate to managing an alarm clock function of a device. The systems and methods for compare a time setting of a new alarm by a user to one or more previous times settings that the alarm has been set to determine whether to warn the user about and/or require the user to confirm the time setting of the new alarm. The systems and methods can detect a user input indicating a first time setting for the alarm clock function. Further, the systems and methods can examine the one or more previous time settings associated with the alarm clock function determine, based on the one or more previous time settings, whether to query the user to confirm an activation of the alarm clock function at the first time setting.

Abstract: A system for determining the amount of life consumed for a tool includes at least one sensor associated with the tool for generating observation data, a memory in operable communication with the at least one sensor, the memory including a database for storing the observation data generated by the sensor, and a processor in operable communication with the memory. The processor includes a model generator that generates a current model for a current run of the tool. The current model includes parameters of a functional approximation of the observation data. The processor also includes a classifier that classifies the current model and a current run estimator that determine the amount of life consumed based on the classification of the current model and a time of use associated with the current run.

Abstract: An information processing apparatus includes a versatile Operating System (OS) that performs a time measurement process in response to a request from an application, a storage unit that stores a process load of the versatile OS and a delay time of the time measurement process in combination, a detecting unit that detects a process load of the versatile OS when the application requests the time measurement process, an acquiring unit that acquires a delay time that corresponds to the process load, which is detected by the detecting unit, as an expected delay time from the storage unit, and a requesting unit that requests the versatile OS to measure a requested measurement time that is obtained by subtracting the expected delay time, which is acquired by the acquiring unit, from a measurement time that is requested by the application.

Abstract: A method of implementing a system time in an electronic device using a timer is disclosed. The method comprises storing a first count reset value in the electronic device; increasing a count value; comparing the first count reset value with the count value at a first particular time; resetting the count value when the count value is the same as the first count reset value at the first particular time; and generating an interrupt request signal when the count value is reset.

Abstract: A method for estimating and correcting or at least reducing phase errors in received ultrasonic signals in an ultrasonic flow meter is disclosed, the method including the steps of: measuring one or more signals in the ultrasonic flow meter, which one or more signals depend on characteristics of one or more ultrasonic transducers in the ultrasonic flow meter, using the one or more measured signals for calculating an estimated phase error value, and using the estimated phase error value for correcting transmission times measured by the ultrasonic flow meter.

Abstract: Methods and systems may provide for a plurality of kinematic sensors to be coupled to a corresponding plurality of shanks of an individual, a processor, and a memory to store a set of instructions. If executed by the processor, the instructions can cause the system to calculate a timed up and go (TUG) time segment based on angular velocity data from the plurality of kinematic sensors. The instructions may also cause the system to calculate a derived parameter based on the angular velocity data, and generate a falls risk assessment based on at least one of the TUG time segment and the derived parameter.

Abstract: A method of detecting a flickering frequency of an ambient light source includes the following steps. First, a light intensity of the light source is sensed in a predetermined time period according to a sampling frequency to obtain a plurality of sample values. Then, the sample values are calculated to obtain a median value. Next, the sample values are binarized according to a result of a comparison between the sample values and the median value to obtain a first sequence. The first sequence is differentiated to obtain a second sequence, and the second sequence includes numbers ?1, 0, and 1. Then, a distance between the same numbers in the second sequence is calculated, and the sampling frequency is divided by the distance to obtain the flickering frequency of the ambient light source. A system of detecting a flickering frequency of an ambient light source is also disclosed herein.

Abstract: In a measuring method in which a sizing device is activated only for a prescribed measurement time (t1) to carry out measurement in a main process that is repeated with a period of a prescribed process time (t0), there are stored an activation drift that is a drift of a measured value after activation of the sizing device and a deactivation drift that is a fluctuation in drifts among different elapsed times, each of the drift being measured when the sizing device is activated after a predetermined time has elapsed since the sizing device is deactivated. A measurement drift section is determined.

Abstract: The present embodiments are generally directed to layers that are useful in imaging apparatus members and components, for use in electrophotographic, including digital, apparatuses. More particularly, the embodiments pertain to an electrophotographic imaging member having a charge transport layer in which a charge transport molecule (CTM) concentration gradient is formed through a single coating pass using only a single charge transport layer solution, and time-of-flight based methods of measuring the CTM gradient through the thickness of the charge transport layer.

Abstract: A system and method is described herein for validating and correcting time codes generated by a plurality of sensors in a proximity-based ad hoc network. The time code information is used to correlate data produced by the sensors in a manner that is useful for location tracking. By validating and correcting the time codes, the system and method improves the integrity of such time code information and any location information generated therefrom.

Abstract: A method and apparatus for estimating a position distribution of radiation emission The method and apparatus include obtaining a time difference between radiations detected by a pair of detectors, and creating a probability distribution function (PDF) indicating the probability of where the radiations actually were or may have been emitted. The PDF may be created based on the time difference and timing resolutions of the pair of detectors.

Abstract: A system and a method for associating measurements from a wellbore with times and depths is provided. Tools located in a wellbore obtain the measurements and provide time data used to determine the times. The tools and a surface clock may be synchronized. The times may be used to associate the measurements with corresponding depths of the wellbore.

Abstract: A method to compensate drying time in an electric or gas dryer machine, which comprises the steps of: read the operator parameters (dryness level, cycle type, heat level); begin a timer to measure time between beginning and Trtv; determine the load weight and the type of restrictions of the dryer; determine the dryness target voltage and the minimum drying time by means of a table of predetermined values based on the previous data; store the values in a memory; determine that the detected voltage be equal to the target voltage; calculate the additional time as a function of the heat factor and of the data previously determined; compare (Tminimum-Trtv) versus additional time and use the greater; and, add the additional time to the Trtv as compensation time.

Abstract: A method of calculating a transmission delay value for data transmitted from a first device to a second device across a communications link. The method involves calculating a plurality of measured values representing the transmission delay measured by the second device over time; detecting a minimum boundary of the measured values; and deriving the transmission delay value from the minimum boundary. The transmission delay value may be used to synchronize the clock signal of the second device to the clock signal of the first device.

Abstract: Systems and methods for detecting the failure of a precision time source using an independent time source are disclosed. Additionally, detecting the failure of a GNSS based precision time source based on a calculated location of a GNSS receiver is disclosed. Moreover, the system may be further configured to distribute a time derived from the precision time source as a precision time reference to time dependent devices. In the event of a failure of the precision time source, the system may be configured to distribute a time derived from a second precision time source as the precision time signal during a holdover period.

Abstract: Systems and methods are provided that are capable of synchronizing an industrial process. The industrial process may include a plurality of process levels. A visualization group may be displayed, showing the various levels of a process. A transition group may be graphically defined that allows for the linking of the transitions between the various process levels. In certain embodiments, sequential function charts (SFC) may include expanded capabilities that allow for the visual definition, editing, and review of the transition groups. Such SFC embodiments may be capable of process flow synchronization across any levels of the modeled process.

Abstract: A method of monitoring the use of exercise equipment at an exercise facility having a plurality of items of exercise equipment, the method comprising the steps of: providing a plurality of usage monitors, each associated with an item of exercise equipment, monitoring the usage of the plurality of items of exercise equipment concurrently using the usage monitors, and thereby calculating, for at least some of the items of exercise equipment, a measure of the proportion of the period of time during which respective items of exercise equipment are used. In some embodiments, the usage monitors can detect when an item of exercise equipment is occupied, even if it is not being operated, for example using a heat sensor. A graphical representation may be prepared of the usage of items of exercise equipment at each of a plurality of locations within the exercise facility.

Abstract: A system includes a plurality of sensors measuring a physical parameter; a processing unit communicatively coupled to the plurality of sensors and configured to receive sensor data from each of the plurality of sensors; wherein the processing unit is further configured to compare rates of change between sensor data for each individual sensor of the plurality of sensors and each of the other individual sensors of the plurality of sensors; wherein the processing unit is further configured to perform a first action when the rate of change of each of the plurality of sensors is within a first threshold of all of the other plurality of sensors; and wherein the processing unit is further configured to perform a second action when the rate of change of at least one of the plurality of sensors is not within the first threshold of at least another of the plurality of sensors.

Abstract: Methods and systems for detecting an oscillation error are provided. According to one embodiment, a system may include a controller, and a processor communicatively coupled to the controller. The processor may be configured to detect an oscillatory event and increment a delay timer based on a duration of the oscillatory event. The delay timer may be set to a predetermined delay value. Additionally, the processor may be configured to determine that the delay timer exceeds the predetermined delay value and, based on the determination, declare the oscillation error.

Abstract: A method for improving accuracy of a time estimate from a memory device is disclosed. In one embodiment, a memory device receives a time stamp and measures active time with respect to the received time stamp. The memory device determines accuracy of previously-measured active time and generates a time estimate using the measured active time, the accuracy of previously-measured active time, and the received time stamp. In another embodiment, measured active time is adjusted, with or without generating a time estimate. Other embodiments are disclosed, and each of the embodiments can be used alone or together in combination.

Abstract: A monitoring system may be used to monitor machining of a workpiece. In some embodiments, the monitoring system may use an acoustic emission sensor to measure acoustic emissions from the machining and generate an acoustic emission signal. The acoustic emission signal may be compared to a master signal using several techniques, such as a Multi-Zone Strategy method. The Multi-Zone Strategy method may comprise generating a plurality of zones of the measured signal and generating a plurality of zones of a master signal to create a plurality of measured and master signal levels and thresholds. A measured signal level for each zone may be compared to a master signal level for each zone to determine whether the measured signal level differs from the master signal level by no more a predetermined percentage, which acts as a threshold for triggering notification of out of tolerance zones.

Abstract: A method of estimating the time of flight of a burst signal includes: receiving the burst signal; determining the slope of the phase characteristic of the Fourier transform of the received burst signal; and estimating the time-of-flight of the burst signal from the slope of the phase characteristic of the Fourier transform of the received burst signal.

Abstract: A physical quantity measuring apparatus includes: a signal input module receiving an input signal having consecutive pulses; a low resolution clock signal generator generating a low resolution clock signal; a high resolution clock signal generator generating a high resolution clock signal; a gate time generator outputting gate time signals at a predetermined interval; a low resolution clock signal synchronizer generating a low resolution clock synchronization signal; a low resolution counter counting the number of rising edges of the low resolution clock signal; a high resolution clock signal generation controller outputting the high resolution clock signal as a gated clock signal; a high resolution clock signal synchronizer generating a high resolution clock synchronization signal; and a high resolution counter counting the number of rising edges of the gated clock signal.

Abstract: A process monitoring system may include: a storage unit configured to store time-sequence data, which is output from a field device located in a plant for measuring a state quantity, and log data, which includes handing procedures performed in past; a prediction unit configured to predict a time variation of the state quantity by using the time-sequence data output from the field device; and an extraction unit configured to extract the time-sequence data similar to the time variation of the state quantity, which has been predicted by the prediction unit, from the time-sequence data, which has been stored in the storage unit, the extraction unit being configured to extract the handling procedures, which has been performed at a time, when the time-sequence data that has been extracted is obtained, from the log data that has been stored in the storage unit.

Abstract: A photoelectric sensor comprises a control unit which performs a measuring process for data on an amount of light input from a light-receiving unit. The control unit measures the length TPS of period (from point a to point d) from when measurement data starts to change in the direction of a threshold P0 to when the amount of received light returns to the level at which the measurement data started to change, and the length TON of period (from point b to point c) for which the detection signal is ON-level. The control unit then outputs information on a margin for TPS with respect to TON on a display unit provided for the photoelectric sensor or to an external device in order to display them.

Abstract: A method and apparatus for comparing event data sets. A method, system and computer program for comparing event data sets comprising: calculating one or more derivatives for each event in a first and second set of events; classifying each event by the calculated derivatives; and evaluating a similarity of the first and second sets of events based on the classifications of the respective events.