Abstract: An apparatus and method for detecting program plagiarism through memory access log analysis is provided. A data extractor extracts an access log of an original program and an access log of a target program to be compared with the original program from a memory accessed by the programs. A common string detector enumerates values, which are obtained from the access logs extracted from the original program and the target program, into strings and detects a common string that commonly exists in the strings. A discontinuity calculator calculates a discontinuity value that indicates a distance between the strings by using an array of the detected common strings. A plagiarism determining unit determines that the target program is plagiarized if the calculated discontinuity value is less than a predetermined reference value.

Abstract: A device for fusing a predetermined toner image on a paper and which electrically insulates a heating body of a fusing unit from a power supply unit by heating the heating body using an induced current generated by a transformer. The fusing device includes an insulation unit for generating an induced current in response to an alternating current, a heating body heated by the generated induced current, a toner fusing unit which fuses the toner image on the paper using the heat received from the heating body, and a tube-expansion adhesion portion closely adhering the heating body to the toner fusing unit using a predetermined tube-expansion pressure.

Abstract: An analog control application specific integrated circuit (ASIC) apparatus for a high voltage power supply (HVPS) in an image for apparatus, and a method for controlling the HVPS are provided. The HVPS includes a transformer transforming an AC signal to a high voltage signal and a voltage doubler outputting a DC high voltage for the HVPS. The ASIC includes an analog control circuit configured as a one-chip ASIC that converts a predetermined DC level signal to a high frequency switching signal using a switching component and outputs the converted high frequency switching signal to a primary winding of the transformer. If the high voltage output signal output from the voltage doubler is not feedbacked, the switching component high frequency switches a received driving signal of a gate driver, and outputs the high frequency switched signal to the transformer.

Abstract: A fusing apparatus in an image forming apparatus that heats a fusing unit by applying an induced current is provided. The flicker characteristics of the fusing apparatus are improved by gradually increasing the amount of induced current applied to the fusing unit for a predetermined amount of time so that the amount of induced current applied to the fusing unit is prevented from severely varying. The fusing apparatus comprises a fusing unit which is resistance-heated or induction-heated by applying an induced current and fuses toner onto paper using the heat. The fusing apparatus further comprises a pulse width modulation (PWM) signal generation unit which generates a PWM signal in response to the ON signal so that the amount of induced current input to the fusing unit gradually increases to a reference current.

Abstract: A fusing device for fusing a predetermined toner image on paper, and which controls the heating range of a fusing unit by inputting an eddy current generated by a transformer to a terminal corresponding to the size of paper selected from a plurality of terminals of the fusing unit. The fusing device includes a power supply unit to which a predetermined alternating current is input and which generates an induced current in response to the input alternating current, a fusing unit being resistance-heated and induction-heated by the induced current and fusing the toner image on the paper using the generated heat, and a controller for controlling the induced current supplied to the fusing unit according to the size of the paper.

Abstract: A phase controlling device of reduced cost, a fuser controlling device including the phase controlling device, and a phase controlling method. The phase controlling device includes: a first signal generating unit generating an error signal that corresponds to a difference between the reference temperature of the fuser and the actual temperature of the fuser; a pulse generating unit generating a sawtooth wave pulse signal that increases with time during a half period of the AC power; and a control signal generating unit comparing the error signal and the sawtooth wave pulse signal and outputting a phase control signal controlling phase of the AC power. The pulse generating unit generating an increasing sawtooth wave pulse may have a relatively simple circuit configuration relative to that of the pulse generating unit generating a decreasing sawtooth wave pulse, thereby reducing manufacturing costs.

Abstract: An apparatus to generate a high voltage includes a switching part to control a voltage induced in a secondary coil of a power transforming part, by interrupting a current in a primary coil of the power transforming part, a digital controlling part to control the interruption operation of the switching part according to supplied control data. The switching part, the digital interfacing part and the digital controlling part may be embodied in an ASIC chip (application-specific integrated circuit). An optimum control according to an output state of the apparatus is easily achieved, manufacturing time for tuning each parameter is reduced and heat generation in the apparatus is reduced.

Abstract: Provided is a parallel program execution method in which in order to reflect structural characteristics of a multithreaded processor-based parallel system, performance of the parallel loop is predicted while compiling or executing using a performance prediction model and then the parallel program is executed using an adaptive execution method.

Abstract: An apparatus to generate a high voltage includes a switching part to control a voltage induced in a secondary coil of a power transforming part, by interrupting a current in a primary coil of the power transforming part, a digital controlling part to control the interruption operation of the switching part according to supplied control data. The switching part, the digital interfacing part and the digital controlling part may be embodied in an ASIC chip (application-specific integrated circuit). An optimum control according to an output state of the apparatus is easily achieved, manufacturing time for tuning each parameter is reduced and heat generation in the apparatus is reduced.

Abstract: An image printer using a common filter to remove harmonic waves generated at a common operating frequency band of a fixing module to fix toner onto a print medium using high frequency power generated from a high frequency generator and a switch mode power supply module to supply operating power to the high frequency generator. The image printer includes a fixing module to fix toner to a print medium using high frequency power generated from a high frequency generator, a switch mode power supply module to supply operating power to the high frequency generator, and a band pass filter to filter harmonic waves of a common operating frequency band of the fixing module and the switch mode power supply module.

Abstract: A fixing device of an image forming apparatus includes a fixing roller rotatably mounted on a moving path of a printing medium having a toner image transferred thereon to fuse the toner image on the printing medium, a heater mounted in the fixing roller to generate a magnetic field by applied voltage, thus heating the fixing roller, and at least one magnetic core disposed around the fixing roller to concentrate, onto the fixing roller, the magnetic field generated by driving the heater. Accordingly, a density difference of the magnetic field generated by the heater is minimized by disposing the at least one magnetic core around the fixing rollers, thus enabling a uniform fixing temperature.

Abstract: A fusing roller and a fusing apparatus having the same are provided. The fusing roller includes: an induced coil, which generates an alternating magnetic flux that varies depending on an input alternating current; a heating roller, which is heated by an eddy current that is generated by the alternating magnetic flux; and a compensator, which compensates for the eddy current generated where it is located.

Abstract: A fusing roller and a fusing apparatus having the fusing roller are provided, wherein the fusing roller includes a coil unit, which generates resistive heat and an alternating magnetic flux in response to an alternating current input thereto, a heating roller unit, which generates an eddy current in response to the alternating magnetic flux and generates induced heat in response to the eddy current, and a contact unit, which is formed of a non-magnetic material in the fusing roller and which firmly contacts the coil unit with the heating roller unit.

Abstract: A fusing roller and a fusing apparatus using the same are provided. The fusing roller includes a coil unit resistance heated by a predetermined alternating current, and generating an alternating magnetic flux by the alternating current. A heating roller unit is heated by an induced current generated by the alternating magnetic flux. An adhering unit is formed of a non-magnetic material and is installed to contact the inside of the coil unit to elastically bias the coil unit toward the heating roller unit to adhere the coil unit onto the heating roller unit.

Abstract: A fusing roller and a fusing apparatus using the same are provided. The fusing roller includes a coil unit resistance heated by a predetermined alternating current, and an alternating magnetic flux is generated by the alternating current. A heating roller unit is heated by an induced current generated by the alternating magnetic flux. End caps are installed on both ends of the heating roller unit and have electrodes for receiving power from an external power source. Reduction units are formed on both ends of the coil unit to reduce contact resistance generated when the coil unit contacts the electrodes.

Abstract: A power supply, which outputs a plurality of voltages in order to improve the cross regulation between output voltages and at the same time reduce the amount of electric power consumed, and an image forming device having the same are disclosed. The power supply comprises a power converter, which generates a first output power source and a second output power source in response to an external power supply and a power control signal, respectively; a power output part, which comprises output parts to rectify and smooth each of the first and second output power sources; a first output controller, which receives the first output power source feedback from the power output part to generate the power control signal; and a second output controller, which receives the second output power source feedback from the power output part to control to operate the power output part in stable mode.

Abstract: A phase controlling device of reduced cost, a fuser controlling device including the phase controlling device, and a phase controlling method. The phase controlling device includes: a first signal generating unit generating an error signal that corresponds to a difference between the reference temperature of the fuser and the actual temperature of the fuser; a pulse generating unit generating a sawtooth wave pulse signal that increases with time during a half period of the AC power; and a control signal generating unit comparing the error signal and the sawtooth wave pulse signal and outputting a phase control signal controlling phase of the AC power. The pulse generating unit generating an increasing sawtooth wave pulse may have a relatively simple circuit configuration relative to that of the pulse generating unit generating a decreasing sawtooth wave pulse, thereby reducing manufacturing costs.

Abstract: An image fixing control system and method are provided comprising a power supply, a power switching unit, a heating roller, in which a temperature detector detects a temperature of the heating roller, and a controller detects a temperature variation slope of the heating roller using the temperature detected by the temperature detector and controls an on and off switching operation of the power switching unit according to the detected temperature variation slope. Accordingly, by varying a duty ratio of power through a phase control using a temperature variation slope of a heating roller, a fine control of a fixing system can be performed. In addition, since a temperature variation, that is, overshoot or undershoot, of the heating roller is reduced, a fixing efficiency can be increased.

Abstract: A power control method and apparatus to heat a heating roller. The power control method includes heating a heating roller provided to fix a toner image of print data in an image forming apparatus, the heating roller having a heating resistor to receive roller power, the power control method includes gradually increasing a maximum level of a source power supplied from an external source up to a specific maximum supply level, and supplying the maximum source power to the heating resistor as the roller power while gradually increasing the maximum level of the source power up to a specific maximum supply level, measuring a surface temperature of the heating roller, and further supplying the source power of which maximum level is equal to the maximum supply level to the heating resistor as the roller power until the measured surface temperature reaches a specific fixing target temperature, and fixing the toner image onto a fed printing medium.

Abstract: A power control method and apparatus to control a heating roller, the power control method including gradually increasing a maximum level of a source power supplied from an external source up to a specific maximum supply level, and supplying the source power to the heating resistor as the roller power, measuring a surface temperature of the heating roller, and supplying the source power having a maximum level equal to the maximum supply level to the heating resistor as the roller power until the measured surface temperature reaches a specific fixing target temperature, supplying the source power having an upper limit of the maximum level equal to a specific fixing property improving level to the heating resistor as the roller power until a printing medium is first fed, and fixing a toner image of print data onto the fed printing medium by using the heating roller.