Abstract:
The present invention provides a method for controlling the operation of a fuel cell system at low temperature that can suitably prevent flooding in a cathode of a fuel cell stack during low-temperature operation, thus improving the operation stability and durability of the fuel cell stack. In preferred embodiments, the present invention provides a method for controlling the operation of a fuel cell system at low temperature, the method comprising determining whether the temperature of a fuel cell stack reaches a normal temperature; calculating, when it is determined that the temperature of the fuel cell stack is lower than the normal temperature, a target temperature at a cathode outlet to maintain water present in a cathode of the fuel cell stack in a vapor phase based on information related to an operation state of the fuel cell stack detected by an operation state detection means; and calculating a target amount of coolant based on the calculated target temperature at the cathode outlet and the information related to the operation state of the fuel cell stack, and controlling the amount of coolant supplied to the fuel cell stack based on the calculated target amount of coolant.
Abstract:
A correlated double sampling (CDS) circuit is provided. The CDS circuit is configured to perform a CDS on a reset signal and an image signal during a CDS phase respectively. The CDS circuit includes a sampling circuit configured to output a difference between a correlated double sampled reset signal and a correlated double sampled image signal, and a feedback unit configured to feedback the difference output from the sampling circuit during a PGA phase to an input of the sampling circuit.
Abstract:
Disclosed are an apparatus and a method for providing an API for sharing contents which provides the API including a function capable of sharing contents during a video call or video conference in a platform including an open web service gateway by using functions provided from the open web service gateway. The apparatus for providing an API for sharing contents during video communication in a platform including an open web service gateway includes: a video communication control unit configured to acquire connection state information of terminals receiving a video communication request; and a contents sharing control unit configured to receive the connection state information of the terminals from the video communication control unit and process a contents sharing request.
Abstract:
Provided is a multichannel transmitter optical module which includes a plurality of light source units configured to generate light, a plurality of an electro-absorption modulators (EAMs) configured to modulate the generated light to an optical signal through a radio frequency (RF) signal, a plurality of RF transmission lines configured to apply the RF signal to the EAMs, and a combiner configured to combine the modulated optical signal. The RF transmission lines are connected to the EAMs in a traveling wave (TW) electrode manner. The multichannel transmitter optical module has alleviated crosstalk and is compactly integrated to have a small size.
Abstract:
A method of cutting light emitting element packages includes preparing a ceramic substrate having a surface on which a plurality of light emitting element chips are mounted and a light-transmitting material layer is formed to cover the plurality of light emitting element chips; partially removing the light-transmitting material layer between the plurality of light emitting element chips along a cutting line by using a mechanical cutting method; and separating individual light emitting element packages by cutting the ceramic substrate along the cutting line by using a laser cutting method.
Abstract:
Provided are a distributed feedback laser diode and a manufacturing method thereof. The distributed feedback laser diode includes a first area having a first grating layer disposed in a longitudinal direction, a second area disposed adjacent to the first area and having a second grating layer disposed in the longitudinal direction, and an active layer disposed over the first and second areas. Coupling coefficients of the first and second grating layers are made different in the first and second areas by a selective area growth method. The distributed feedback laser diode includes grating layers each having an asymmetric coefficient and is implemented within an optimal range capable of obtaining both a high front facet output and stable single mode characteristics. Thus, high manufacturing yield and low manufacturing cost can be achieved.
Abstract:
The present invention provides a pulverizing screw, a pulverizing casing and a pulverizer having the same. The pulverizing screw includes a rotating shaft and a drive blade which extends from the rotating shaft in a spiral shape. The drive blade rotates in the pulverizing casing in such a manner as to maintain a predetermined distance between the drive blade and the inner surface of the pulverizing casing to prevent the drive blade from being impeded by the inner surface of the pulverizing casing. The drive blade extends from a first end of the rotating shaft in a spiral shape surrounding the rotating shaft in a clockwise or counterclockwise direction and is connected to a second end of the rotating shaft. The pulverizing casing comprises a spherical body having a space therein. The pulverizing screw is installed in the spherical body so as to be rotatable.
Abstract:
Disclosed therein is a method for preparing a polyacrylonitrile-based polymer for preparation of carbon fiber having a melting point controlled by selecting an optimal energy of microwave, and a method for preparing a carbon fiber through melt spinning using the preparation method for polyacrylonitrile-based polymer. The present invention uses microwave to control the properties of the polyacrylonitrile-based polymer in a simplified way and prepare the polymer optimized for preparation of carbon fiber precursor through melt spinning for a short polymerization time, and provides a means for mass production of the polyacrylonitrile-based polymer being suitable for melt spinning at a temperature lower than the stabilization temperature and acquiring properties adequate to preparation of carbon fiber through stabilization. Hence, the present invention is expected to contribute to mass production of high-performance carbon fibers at reduced cost.
Abstract:
An image sensor includes a pixel array including a plurality of pixels which are arranged in a matrix of a plurality of rows and columns and each of the plurality of pixels being configured to convert intensity of incident light into an electrical image signal; and an extended counting analog-to-digital converter configured to perform a first analog-to-digital conversion to provide a digital signal from an output signal of the pixel array, to obtain a residue using the output signal of the pixel array and the digital signal, and to perform a second analog-to-digital conversion using the residue.
Abstract:
Provided are a THz-wave generation/detection module and a device including the same, which increase heating efficiency and are miniaturized. The module includes a photomixer chip, a lens, a PCB, and a package. The photomixer chip includes an active layer, an antenna, and a plurality of electrode pads. The lens is disposed on the photomixer chip. The PCB includes a plurality of solder balls connected to the electrode pads, under the photomixer chip. The package surrounds a bottom and side of the PCB, and dissipates heating of the active layer, which is transferred from the electrode pad of the photomixer chip to the PCB, to outside.