Abstract: A compressor, a monitoring system and a method of monitoring a compressor that make it possible to monitor the remaining lifetime of a semiconductor element of a motor control system while the processing load is reduced are provided. A compressor (1) includes: a motor control system (10) that controls the rotation speed of a motor (2); a compressor body (3) that compresses air by being driven by the motor (2); a pressure sensor (20) that is provided on the discharge side of the compressor body (3); and a running controller (11) that performs switching between load running and no-load running on the basis of the pressure sensed by the pressure sensor (20).

Abstract: A compressor, a monitoring system and a method of monitoring a compressor that make it possible to monitor the remaining lifetime of a semiconductor element of a motor control system while the processing load is reduced are provided. A compressor (1) includes: a motor control system (10) that controls the rotation speed of a motor (2); a compressor body (3) that compresses air by being driven by the motor (2); a pressure sensor (20) that is provided on the discharge side of the compressor body (3); and a running controller (11) that performs switching between load running and no-load running on the basis of the pressure sensed by the pressure sensor (20).

Abstract: A method for detecting a predetermined behavior during a domain name registration or a domain resolution activity includes identifying one or more dimensions to be tracked. One or more metrics for each dimension is/are identified. A first time series for each of the metrics is generated. One or more first outliers in at least one of the first time series is detected. One or more sets of metrics is generated, each set including a combination of two or more of the metrics. A second time series for each of the metrics in the one or more sets of metrics is generated. One or more second outliers in at least one of the second time series is/are detected.

Abstract: A method for detecting a domain name that is associated with malicious behavior includes receiving domain data for a plurality of domain names including a first domain name and a plurality of similar domain names. The domain data includes a first attribute and a second attribute of the first domain name and the similar domain names. The first attribute of the first domain name is compared to the first attributes of the similar domain names to produce a first value. The second attribute of the first domain name is compared to the second attributes of the similar domain names to produce a second value. The first value and the second value are combined to produce a combined value. A likelihood that the first domain name is associated with malicious behavior is determined based on the combined value.

Abstract: The purpose of the present invention is to provide an electric motor system such that loss of synchronism of an inverter-driven synchronous motor with no magnetic pole position sensor can be easily detected. In order to achieve the purpose, the present invention pertains to an electric motor equipped with a synchronous motor, an inverter having a power conversion device for driving the synchronous motor, and a load connected to the synchronous motor, and is configured such that loss of synchronism of the synchronous motor is determined on the basis of a direct-current voltage in the power conversion device.

Abstract: In one embodiment, a DNS service provider determines that a domain name being configured by a user is a lame delegated domain name and manages the configuration of the domain name accordingly. In operation, when a user of the DNS service provider attempts to provide configuration information for a domain name, the DNS service provider determines whether the domain name is lame delegated to the DNS service provider. If the domain name is lame delegated, then, to avoid passing control of the domain name to a nefarious entity, the DNS service provider performs a verification process to determine whether the user is the rightful owner of the domain name. The user is allowed to configure the domain name within the DNS service provider when the user is the rightful owner of the domain name.

Abstract: Systems and methods for detecting spoofed traffic include determining a first hop count of a first data query from a first transmitting device to a first server, determining a second hop count of a second data query from the first transmitting device to a second server, determining a third hop count of a third data query appearing to be from the first transmitting device to the first server, and determining a fourth hop count of a fourth data query appearing to be from the first transmitting device to the second server. The third and fourth hop counts are compared to the first and second hop counts, respectively. It is determined whether the third hop count differs from the first hop count by more than a predetermined amount.

Abstract: The purpose of the present invention is to provide an electric motor system such that loss of synchronism of an inverter-driven synchronous motor with no magnetic pole position sensor can be easily detected. In order to achieve the purpose, the present invention pertains to an electric motor equipped with a synchronous motor, an inverter having a power conversion device for driving the synchronous motor, and a load connected to the synchronous motor, and is configured such that loss of synchronism of the synchronous motor is determined on the basis of a direct-current voltage in the power conversion device.

Abstract: A method for detecting a predetermined behavior during a domain name registration or a domain resolution activity includes identifying one or more dimensions to be tracked. One or more metrics for each dimension is/are identified. A first time series for each of the metrics is generated. One or more first outliers in at least one of the first time series is detected. One or more sets of metrics is generated, each set including a combination of two or more of the metrics. A second time series for each of the metrics in the one or more sets of metrics is generated. One or more second outliers in at least one of the second time series is/are detected.

Abstract: Systems and methods for detecting spoofed traffic include determining a first hop count of a first data query from a first transmitting device to a first server, determining a second hop count of a second data query from the first transmitting device to a second server, determining a third hop count of a third data query appearing to be from the first transmitting device to the first server, and determining a fourth hop count of a fourth data query appearing to be from the first transmitting device to the second server. The third and fourth hop counts are compared to the first and second hop counts, respectively. It is determined whether the third hop count differs from the first hop count by more than a predetermined amount.

Abstract: Disclosed is a motor control apparatus for controlling a synchronous motor, which includes a receiver section for receiving the value detected by a temperature sensor installed inside the synchronous motor. The synchronous motor is started up with the current fed into it, whose magnitude is changed in accordance with the temperature received by the receiver section at the time of starting up the synchronous motor. In this way, the stable startup of the synchronous motor can be guaranteed and the useful life of the semiconductor elements can also be prolonged.

Abstract: Disclosed is a motor control apparatus for controlling a synchronous motor, which includes a receiver section for receiving the value detected by a temperature sensor installed inside the synchronous motor. The synchronous motor is started up with the current fed into it, whose magnitude is changed in accordance with the temperature received by the receiver section at the time of starting up the synchronous motor. In this way, the stable startup of the synchronous motor can be guaranteed and the useful life of the semiconductor elements can also be prolonged.

Abstract: A synchronous motor driving apparatus having a power converter which applies AC variable voltages having variable frequency to a synchronous motor includes a pulsating current application unit for applying pulsating current to the synchronous motor and a magnetic pole position presumption unit. The magnetic pole position presumption unit detects two current values ?Idcp1 and ?Idcp2 on the positive side and two current values ?Idcn1 and ?Idcn2 on the negative side of the pulsating current and presumes the magnetic pole position of the synchronous motor on the basis of difference between change rates of ?Idcp1??Idcp2 and ?Idcp1??Idcp2.

Abstract: A motor drive system without any portion for directly detecting the rotor position, rotation speed and motor phase currents, capable of realizing a high-performance variable speed drive even at high carrier frequencies. When detecting a current from a DC power supply of an inverter for driving a motor, applied voltages and frequencies to the motor are controlled based on sampled values by sampling a current flowing as intermittent pulses in the vicinity of each power conduction time period.

Abstract: A synchronous motor driving apparatus having a power converter which applies AC variable voltages having variable frequency to a synchronous motor includes a pulsating current application unit for applying pulsating current to the synchronous motor and a magnetic pole position presumption unit. The magnetic pole position presumption unit detects two current values ?Idcp1 and ?Idcp2 on the positive side and two current values ?Idcn1 and ?Idcn2 on the negative side of the pulsating current and presumes the magnetic pole position of the synchronous motor on the basis of difference between change rates of ?Idcp1??Idcp2 and ?Idcp1??Idcp2.

Abstract: An AC motor control apparatus that is applicable to commonly used PM motors and capable of detecting the magnetic pole position with simple algorithm. The AC motor control apparatus comprises an inverter for applying arbitrary AC power to an AC motor and a controller for sending a control signal to the inverter. The controller comprises a ripple current generator for supplying a ripple current to the AC motor and a magnetic pole position estimator. The magnetic pole position estimator observes at least two current values of the ripple current for both positive and negative sides of the ripple current to estimate the magnetic pole position of the AC motor.

Abstract: The object of the invention is to inhibit the axial displacement caused by the insufficiency of a control response angular frequency of a frequency arithmetic unit of a synchronous motor and realize high-precision torque control also in acceleration/deceleration. To achieve the object, the axial displacement of the synchronous motor caused by the insufficiency of the control response angular frequency of the frequency arithmetic unit is estimated in consideration of the control response angular frequency and input ??c3 (=??c1+??c2) including an estimated value ??c2 in addition to an axial displacement operated value ??c1 to the frequency arithmetic unit is acquired. Hereby, even if the frequency arithmetic unit has an insufficient control response angular frequency, the quantity of axial displacement which will be caused by the insufficiency is estimated as a second axial displacement signal ??c2, is added and input.

Abstract: An AC motor control apparatus that is applicable to commonly used PM motors and capable of detecting the magnetic pole position with simple algorithm. The AC motor control apparatus comprises an inverter for applying arbitrary AC power to an AC motor and a controller for sending a control signal to the inverter. The controller comprises a ripple current generator for supplying a ripple current to the AC motor and a magnetic pole position estimator. The magnetic pole position estimator observes at least two current values of the ripple current for both positive and negative sides of the ripple current to estimate the magnetic pole position of the AC motor.

Abstract: The object of the invention is to inhibit the axial displacement caused by the insufficiency of a control response angular frequency of a frequency arithmetic unit of a synchronous motor and realize high-precision torque control also in acceleration/deceleration. To achieve the object, the axial displacement of the synchronous motor caused by the insufficiency of the control response angular frequency of the frequency arithmetic unit is estimated in consideration of the control response angular frequency and input &Dgr;&thgr;c3 (=&Dgr;&thgr;c1+&Dgr;&thgr;c2) including an estimated value &Dgr;&thgr;c2 in addition to an axial displacement operated value &Dgr;&thgr;c1 to the frequency arithmetic unit is acquired. Hereby, even if the frequency arithmetic unit has an insufficient control response angular frequency, the quantity of axial displacement which will be caused by the insufficiency is estimated as a second axial displacement signal &Dgr;&thgr;c2, is added and input.

Abstract: A motor drive system without any portion for directly detecting the rotor position, rotation speed and motor phase currents, capable of realizing a high-performance variable speed drive even at high carrier frequencies. When detecting a current from a DC power supply of an inverter for driving a motor, applied voltages and frequencies to the motor are controlled based on sampled values by sampling a current flowing as intermittent pulses in the vicinity of each power conduction time period.