Abstract: A driving circuit for a light emitting diode connected to a TRIAC dimmer configured to modulate an input AC voltage depending on a selected dimming level including a rectifier configured to full-wave rectify the modulated AC voltage output from the TRIAC dimmer to generate and output a driving voltage, a driving module configured to receive the driving voltage of the rectifier to detect the selected dimming level and drive a plurality of light emitting diode groups depending on the detected dimming level, and a bleeder circuit configured to provide a bleeder current to the TRIAC dimmer, in which the bleeder circuit is configured to provide the bleeder current only for a preset on-duty time.

Abstract: A lighting apparatus including a light emitting diode connected to a dimmer configured to modulate an input AC voltage depending on a selected dimming level, a rectifier configured to full-wave rectify the modulated AC voltage output from the dimmer to generate and output a driving voltage, a driving module configured to receive the driving voltage of the rectifier to detect the selected dimming level, and select one of three driving modes of a stop mode, a resistance driving mode, and a sequential driving mode depending on the detected dimming level, and a plurality of light emitting diode groups configured to emit light depending on a control of the driving module.

Abstract: Disclosed is a method for stabilizing a quantum cryptography system, which includes: determining whether the quantum cryptography system operates in a stabilized state, on the basis of a bit error rate or a key rate of the quantum cryptography system; and readjusting an arrival time of a gate pulse or a laser operation time so that an arrival time of a single photon for a photon detector is aligned with the arrival time of the gate pulse, when the quantum cryptography system does not operate in a stabilized state. Here, the quantum cryptography system may be a two-way quantum cryptography system.

Abstract: An AC-driven LED lighting apparatus includes: a triac dimmer to generate a modulated AC voltage by modulating a phase of AC power according to a selected level of dimming; a rectifying circuit to generate drive voltage by full-wave-rectifying the AC voltage having the phase modulated by the triac dimmer; a dimming level detector to detect a dimming level according to the drive voltage; a phase cut reference setting unit for setting a phase cut reference value; and a LED driving module for constant-current-controlling a plurality of LED groups by comparing the detected dimming level with the phase cut reference value, wherein the light emitting element driving module comprises a LED current blocking unit for blocking a drive current supplied to the plurality of LED groups when the dimming level is lower than the phase cut reference value.

Abstract: Disclosed herein are a driving circuit and a lighting apparatus for a light emitting diode capable of improving a flicker, light efficiency, and electrical characteristics. The disclosed driving circuit for a light emitting diode includes: a dimmer modulating an AC voltage input depending on a selected dimming level; a rectifier full-wave rectifying the modulated AC voltage output from the dimmer to generate and output a driving voltage; and a driving module receiving the driving voltage of the rectifier to detect the selected dimming level and controlling a driving mode of a plurality of light emitting diode groups depending on the detected dimming level, in which the driving module selects one of a resistance driving mode driving all the plurality of light emitting diode groups and a sequential driving mode sequentially driving the plurality of light emitting diode groups to improve light efficiency and electrical characteristics.

Abstract: An AC-driven LED lighting apparatus includes: a triac dimmer to generate a modulated AC voltage by modulating a phase of AC power according to a selected level of dimming; a rectifying circuit to generate drive voltage by full-wave-rectifying the AC voltage having the phase modulated by the triac dimmer; a dimming level detector to detect a dimming level according to the drive voltage; a phase cut reference setting unit for setting a phase cut reference value; and a LED driving module for constant-current-controlling a plurality of LED groups by comparing the detected dimming level with the phase cut reference value, wherein the light emitting element driving module comprises a LED current blocking unit for blocking a drive current supplied to the plurality of LED groups when the dimming level is lower than the phase cut reference value.

Abstract: A light-emitting diode (LED) lighting apparatus including at least one LED group including a plurality of LEDs, a rectifier configured to rectify an alternating current (AC) voltage and generate a driving voltage for the at least one LED group, and a system-in-package (SIP) configured to drive and control the at least one LED group, in which the SIP is connected to the at least one LED group and the rectifier, and includes a driving module, a functional module, and a first resistor disposed on a single substrate.

Abstract: An X-ray imaging apparatus includes an X-ray generator configured to emit X-rays to a subject; an X-ray detection panel including a plurality of light receiving elements each configured to receive X-rays that have passed through the subject, convert the X-rays into an electric signal, and output the electric signal, and a plurality of capacitor modules respectively corresponding to the plurality of light receiving elements, each of the plurality of capacitor modules including a plurality of capacitors connected to a corresponding one of the light receiving elements and configured to store the electric signal output from the corresponding light receiving element in at least one capacitor of the plurality of capacitors; and an image processor configured to read out the electric signal stored in the at least one capacitor of each of the plurality of capacitor modules to generate at least one X-ray image.

Abstract: The device for cooperation control of the EMS and the DMS comprises: a calculation unit for calculating an AQI index on the basis of target system information and power flow calculation data; a determination unit which determines whether or not to perform reactive power cooperation control switching of the DMS on the basis of the calculated AQI index and the amount of needed local reserve reactive power (Qreq), and which determines a suppliable reactive power capacity on the basis of the amount of needed local reserve reactive power (Qreq) and a suppliable reactive power range; and a control unit which transmits a cooperation control mode switching control signal so as to switch the DMS to a reactive power cooperation control mode if it is determined that reactive power cooperation control switching of the DMS is to be performed, and which controls the DMS to supply reactive power.

Abstract: An LED lighting apparatus according to exemplary embodiments includes a rectification circuit configured to rectify a modulated AC voltage to generate a drive voltage, an LED driving module connected to a plurality of LED groups and configured to apply a drive current to at least one of the plurality of LED groups according to a level of the drive voltage, and a dimming level detector configured to detect a dimming level corresponding to the drive voltage. The LED driving module is configured to compare the detected dimming level to a reference value and block the drive current based on a result of the comparison.

Abstract: A voltage controlled oscillator (VCO) in a frequency synthesizer generates an output signal having a target frequency by being coarse tuned in accordance with a channel code derived through a binary tree search. Thereafter, the output signal of the VCO may be further tuned using a phase lock loop (PLL) circuit. Each stage of the binary tree search includes a comparison step that determines a channel code bit, and another step that confirms that the channel code converges to a final channel code within an established stage range value.

Abstract: An alternating current sequential drive type LED lighting device having improved flicker performance and being capable of reducing the light output deviation of the LED lighting device generated during operation intervals by removing nonluminous intervals of the LED lighting device by means of a loop-back compensation unit.

Abstract: Disclosed are a light emitting diode (LED) driver circuit having improved flicker performance and an alternating current-driving type LED lighting device including the same. The LED driver circuit can remove an LED off period using a charging and discharging circuit during a compensation period so as to reduce light output deviation of an LED lighting device, and provide a driving voltage to another element of the LED lighting device, using the charging and discharging circuit during an additional discharging period so as to simultaneously improve power efficiency.

Abstract: An apparatus for quantum cryptographic communication includes a light source configured to generate an optical pulse which is transmitted to a plurality of quantum code sending devices, and a quantum entanglement measuring unit configured to receive the optical signal generated from each of the plurality of quantum code sending devices and measure a relation among quantum states of the optical signals received from the plurality of quantum code sending devices; the optical signal being generated by encoding a key to a quantum state of the optical pulse. The apparatus for quantum cryptographic communication may further include a signal direction determining unit, a reflector for reflecting the optical pulse or the optical signal, an arbitrary phase shifter, or a modulator for encoding a digital signal corresponding to the key to the optical pulse.

Abstract: An LED lighting apparatus according to exemplary embodiments includes a rectification circuit configured to rectify a modulated AC voltage to generate a drive voltage, an LED driving module connected to a plurality of LED groups and configured to apply a drive current to at least one of the plurality of LED groups according to a level of the drive voltage, and a dimming level detector configured to detect a dimming level corresponding to the drive voltage. The LED driving module is configured to compare the detected dimming level to a reference value and block the drive current based on a result of the comparison.

Abstract: Disclosed is a communication apparatus including a synchronization signal detector configured to detect a synchronization signal received from other communication apparatus coupled to the communication apparatus, wherein the other communication apparatus sends a quantum signal generated by a first light source to the communication apparatus, and a second light source configured to generate a decoy signal to be added to a quantum signal that is to be sent to the other communication apparatus according to a result of the detection of the synchronization signal.

Abstract: An alternating current sequential drive type LED lighting device having improved flicker performance and being capable of reducing the light output deviation of the LED lighting device generated during operation intervals by removing nonluminous intervals of the LED lighting device by means of a loop-back compensation unit.

Abstract: Disclosed is a method for stabilizing a quantum cryptography system, which includes: determining whether the quantum cryptography system operates in a stabilized state, on the basis of a bit error rate or a key rate of the quantum cryptography system; and readjusting an arrival time of a gate pulse or a laser operation time so that an arrival time of a single photon for a photon detector is aligned with the arrival time of the gate pulse, when the quantum cryptography system does not operate in a stabilized state. Here, the quantum cryptography system may be a two-way quantum cryptography system.

Abstract: An X-ray detector may include a silicon substrate including a first area and a second area; a plurality of pixels in the first area configured to detect X-rays; a control pad in the second area configured to supply a common control signal to the plurality of pixels; and/or a power supply pad in the first area configured to supply a power supply voltage to groups of pixels grouped from among the plurality of pixels.

Abstract: An exemplary embodiment discloses a light-emitting diode (LED) driving circuit including an LED driving module configured to provide a first driving voltage to an LED light emitting module including a first LED group to an n-th LED group, n is an integer which is equal to or larger than 2, and sequentially drive the first LED group to the n-th LED group depending on a voltage level of the first driving voltage and a second driving voltage providing module configured to store some of the first driving voltage and selectively provide a second driving voltage to some of the LED groups other than at least the first LED group to an m-th LED group among the LED groups in a Vfm compensation section, 1?m?n?1, according to a control of the LED driving module.