Abstract: Provided are a novel metallocene-supported catalyst and a method of preparing a polyolefin using the same. The metallocene-supported catalyst according to the present disclosure may be used in the preparation of polyolefins, it may have excellent activity and excellent reactivity with comonomers, and it may prepare olefinic polymers having a high molecular weight and a low molecular weight.

Abstract: The present disclosure provides a method for preparing a supported hybrid metallocene catalyst which can be used to prepare a polyolefin, a supported hybrid metallocene catalyst prepared by using the method, and a method for preparing a polyolefin using the supported hybrid metallocene catalyst.

Abstract: A wireless power transmitting method performed in a wireless power transmitting apparatus wirelessly transmitting power includes determining reception strength of a short-range wireless communication channel, adjusting an interval of a short beacon signal in response to a change in reception strength; and transmitting the short beacon signal at the interval.

Abstract: A wireless power transmitter includes: a converter including a first switch and a second switch, and configured to output alternating current (AC) power to an AC node between the first switch and the second switch; a common resonance capacitor connected to the AC node; and resonators connected to the common resonance capacitor, wherein each of the resonators includes a series capacitor, a resonance coil, and a sub-switch, connected to each other in series, and wherein the resonance coil is configured to transmit the power in a non-contact manner.

Abstract: The present invention relates to ethylene-1-hexene-1-butene terpolymer and a film including the same. The ethylene-1-hexene-1-butene terpolymer according to the present invention has an optimized range of density and melt index and includes 1-hexene and 1-butene as comonomers, and can provide a polymer showing excellent properties by regulating the content ratio of the comonomers in a certain range. Therefore, the film prepared by using the same can be usefully used because it has excellent stickiness, processibility, and falling dart impact strength which are especially suitable for stretch films.

Abstract: A wireless power transmitter includes an inverter member comprising transistors configured to convert input power into alternating current (AC) power; a resonating member comprising a capacitor and a coil, and connected to an outer terminal of the inverter member; a controller configured to provide a switching signal to the plurality of transistors to control the inverter member; and a current limiting part configured to limit a level of a current applied to the inverter member by the input power.

Abstract: There are provided an apparatus apparatus for transmitting power wirelessly. The apparatus for transmitting power wirelessly may include a boosting unit boosting an input voltage, and an inverter unit inverting the boosted voltage output from the boosting unit to transmit power wirelessly. The inverter unit and the boosting unit are controlled by the same switching element.

Abstract: The present invention relates to a supported hybrid catalyst and a method for preparing olefin polymer using the same. Using the supported hybrid catalyst, olefin polymer that maintains excellent mechanical strength of olefin polymer polymerized with the existing metallocene catalyst, but exhibits remarkably improved processibility compared to the existing olefin polymer, can be provided.

Abstract: A wireless power transmitter includes: a converter including switching elements forming a bridge circuit and configured to output an alternating current (AC) voltage in response to control signals; a resonator including a resonant capacitor and a resonant coil, and configured to receive the AC voltage to transmit power wirelessly; and a controller configured to set a dead time at which a magnitude of the AC voltage is substantially zero in response to a signal received from a wireless power receiver.

Abstract: A wireless power transmitter includes a converter, a resonator, and a controller. The converter includes switching elements forming a bridge circuit, and is configured to output an alternating current (AC) voltage in response to control signals. The resonator includes a resonant capacitor and a resonant coil, and is configured to receive the AC voltage to wirelessly transmit power. The controller is configured to perform a first mode operation in which a duty of the control signals is fixed, a frequency of one of the control signals is varied and the control signals are output, and a second mode operation in which a frequency of the control signals is fixed, a duty of one of the control signals is reduced and the control signals are output.

Abstract: A wireless power transmitter includes a converter comprising at least one switching element, and configured to generate boosted input power; a resonator and a controller. The resonator is configured to receive the boosted input power as an alternating current (AC) power, and transmit a ping signal in a detection mode for determining whether any one or both of an external object approaching and a type of the external object. The controller is configured to control the switching element, and gradually increase a duty cycle of a gate signal provided to the switching element, in the detection mode.

Abstract: A wireless power transmitter includes: a converter including switching elements forming a bridge circuit, wherein the converter is configured to output an alternating current (AC) voltage including a frequency determined according to an operating frequency of at least one switching element among the switching elements; a resonator including an inductor and a capacitor, and configured to receive the AC voltage to wirelessly transmit power; and a controller configured to output control signals controlling the switching elements so that the converter performs a first mode operation in which an operating duty cycle is fixed and the operating frequency is varied, and an operation of the converter is switched from the first mode operation to a second mode operation in which the operating frequency is fixed and the operating duty cycle is varied, in response to the operating frequency reaching a first reference frequency.

Abstract: The present invention relates to a transition metal compound that may exhibit high activity in olefin polymerization, and easily control the properties of synthesized olefin polymer such as a chemical structure, molecular weight distribution, a mechanical property, and the like, a catalyst composition comprising the same, and a method for olefin polymerization using the catalyst composition.

Abstract: Provided are an olefin-based polymer having excellent melt strength and a film including the same. The olefin-based polymer according to the present invention may have excellent processability, haze and mechanical properties, and in particular, high melt strength, thereby being usefully applied to films, etc.

Abstract: There is provided a wireless charging system, including: a wireless power transmitting module including at least one power transmitter transmitting power and at least one wireless power receiving module receiving the power, wherein the wireless power transmitting module controls the power, which is transmitted to the wireless power receiving modules corresponding to the power transmitters, from the power transmitters, depending on targeted voltage gains of the wireless power receiving modules corresponding to the power transmitters.

Abstract: Provided is an olefin-based polymer with excellent processability. The olefin-based polymer according to the present invention has a high molecular weight and a broad molecular weight distribution to show excellent processability and improved transparency, thereby being used in desired applications.

Abstract: A method of controlling a wireless power transmitter includes actuating the wireless power transmitter to transmit a beacon signal, determining approach of an external object according to a detected change in the beacon signal, and transmitting ping signals having different frequencies responsive to the determined approach of the external object.

Abstract: A wireless power transmission apparatus includes a resonator configured to be magnetically coupleable to a wireless power reception apparatus; an inverter configured to operate the resonator; and a resonant frequency controller configured to control a resonant frequency of the resonator in response to a change in operating frequency of the inverter.

Abstract: A wireless power-transmitting apparatus, includes a variable resonator; a power transmitter configured to wirelessly transmit power to a wireless power-receiving apparatus using the variable resonator; and a controller configured to determine class information of the wireless power-receiving apparatus and, in response, control the power transmitter to change impedance of the variable resonator according to the class information.

Abstract: A wireless power transmitter includes resonators electrically connected to each other and a resonance frequency varying unit configured to vary resonance frequencies of the resonators based on a change in an amount of power to be sent to a wireless power receiver from the wireless power transmitter.