Abstract: A power generation control system of a fuel cell includes: the fuel cell generating a power through a chemical reaction between fuel and air; a consuming device connected to an output terminal of the fuel cell and consuming the power output from the fuel cell; a converter connected between the fuel cell and the consuming device in series or parallel and adjusting an output voltage of the fuel cell; a supply device supplying the air to the fuel cell; a voltage controller controlling the converter on the basis of a required power or current of the fuel cell required to be output; and a supply controller controlling the supply device on the basis of the required power or current of the fuel cell required to be output.

Abstract: A system for estimating the amount of purge of a fuel cell is provided. The system includes a fuel cell that generates power by receiving hydrogen at an anode side and receives oxygen at a cathode side. A recirculation line is connected with the anode side of the fuel cell, and the gas included hydrogen therein is circulated in the recirculation line. A flow amount estimator estimates the flow amount of gas inside the recirculation line. A purge valve is positioned in the recirculation line and discharges the gas in the recirculation line to the outside when opened. A purge amount estimator estimates the amount of purge for each gas discharged through the purge valve by reflecting the flow amount of the gas estimated by the flow amount estimator.

Abstract: The present invention relates to a method for displaying learning content of a terminal and an application program therefor. The method for displaying learning content of a terminal of the present invention comprises the steps of: displaying text with a group of questions on a first layer; displaying a first question card corresponding to a first question on a second layer; and when a continuous touch gesture in a touch input is received in the second layer, displaying, on the second layer, a second question card corresponding to a second question according to the touch gesture, wherein the question card includes one or more examples that are selectable by a learner. According to the present invention, it is possible to effectively display learning content including a large amount of information such as multiple choice questions on a limited size screen.

Abstract: A carburizing steel includes, based on a total wt % of the carburizing steel: 0.1 wt % or more and 0.3 wt % or less of C (carbon); 2.0 wt % or more and 2.7 wt % or less of Cr (chrome); 0.4 wt % or more of Si (silicon); 0.3 wt % or more and 0.7 wt % or less of Mo (molybdenum); less than 0.7 wt % of Mn (manganese); and 0.6 wt % or more and 1.5 wt % or less of Ni (nickel).

Abstract: A fuel cell hydrogen supply fault diagnosis system is provided. The system includes multiple fuel tanks that store hydrogen therein to supply the hydrogen and a fuel tank valve disposed at each of the fuel tanks and configured to be opened or closed to supply or shut off the hydrogen of the fuel tanks. A pressure sensor measures pressure in a fuel supply line that extends from each of the multiple fuel tanks to be integrally connected to a fuel cell stack. A supply amount estimator then estimates a supply amount of hydrogen supplied to the fuel cell stack and a consumption amount estimator estimates a consumption amount of hydrogen consumed in a reaction in the fuel cell stack or discharged therefrom. A fault detector then detects a hydrogen supply state.

Abstract: A system for estimating purge of a fuel cell includes the fuel cell for generating power by receiving hydrogen at an anode side, and receiving oxygen at a cathode side, a recirculation line connected with the anode side of the fuel cell, and in which gas containing hydrogen therein is circulated, a purge valve positioned in the recirculation line, and for discharging the gas in the recirculation line to outside as the purge valve is opened, a differential pressure calculator for calculating a differential pressure between a front end and a rear end of the purge valve, a speed estimator for estimating a current gas diffusion speed in the recirculation line, and a purge amount estimator for estimating the amount of purge through the purge valve by using the differential pressure calculated by the differential pressure calculator and the gas diffusion speed estimated by the speed estimator.

Abstract: A control method for driving of a fuel cell is provided. The method includes determining whether power generation of the fuel cell is stopped and when the power generation of the fuel cell is stopped, monitoring voltages of multiple unit cells included in the fuel cell. A degree of defect of the unit cells is determined based on the monitored voltages of the unit cells.

Abstract: The present disclosure relates a brake disc and a method of manufacturing the same, in which the depth of the coating layer containing a nitride is adjustable and corrosion resistance and wear resistance can be improved. A brake disc according to an embodiment of the present disclosure includes: a disc base material made of gray cast iron; and a coating layer formed on a surface of the disc base material and including a nitride produced as nitrogen is diffused into a ferrite matrix structure.

Abstract: An apparatus and a method for segmenting a steel microstructure phase are provided. The apparatus includes a storage configured for storing a machine learning algorithm and a processing device that segments a microstructure phase using the machine learning algorithm. The processing device is configured to receive label data, to learn a machine learning model by use of the label data as learning data for the machine learning model, and to segment a phase of a steel microstructure image by use of the learned machine learning model.

Abstract: A copper alloy for valve seats, and more particularly a copper alloy for valve seats with improved wear resistance, contains 12 to 24% by weight of Ni, 2 to 4% by weight of Si, 7 to 13% by weight of Cr, 20 to 35% by weight of Fe, and a balance of Cu and other impurities.

Abstract: A fuel cell control method and are provided. The method includes collecting state data of a fuel cell stack and then estimating an effective catalytic amount of the fuel cell stack based on the collected state data. A fuel cell system is operated based on the estimated effective catalytic amount to thus optimize the efficiency of the system.

Abstract: A hydrogen supply control system for a fuel cell is provided. The system includes a fuel cell stack that generates electricity using supplied hydrogen and air and a recirculation line that supplies hydrogen discharged from an outlet of the fuel cell stack back to an inlet of the fuel cell stack. A purge valve is disposed at an outlet side of the fuel cell stack of the recirculation line and discharges hydrogen in the recirculation line to the outside as the outlet is opened. A recirculation determining processor determines a recirculation state of the recirculation line and a concentration estimator estimates a purge amount for each gas, which is purged by the purge valve, based on the determined recirculation state and estimates a concentration of hydrogen in the recirculation line based on the estimated purge amount for each gas.

Abstract: A condensate water drain control system for fuel cells includes a fuel cell stack configured to generate electric power through chemical reaction, a fuel supply line configured to recirculate fuel discharged from the fuel cell stack together with fuel introduced from a fuel supply valve, a water trap located in the fuel supply line, the water trap being configured to collect condensate water discharged from the fuel cell stack, a drain valve configured to discharge the condensate water stored in the water trap to the outside when opened, and a drain controller configured to determine whether the fuel supply valve is controlled such that pressure in the fuel supply line is maintained before the drain valve is opened and to sense discharge of fuel from the fuel supply line through the drain valve upon determining that the pressure is maintained.

Abstract: A system and method for controlling hydrogen purging of a fuel cell are provided. The method includes calculating a hydrogen supply amount and estimating a hydrogen consumption amount. An estimated hydrogen concentration is then corrected when a difference between the calculated hydrogen supply amount and the estimated hydrogen use amount is greater than a predetermined threshold value.

Abstract: A brake disk includes a basic material formed of gray cast iron, a decarburized layer formed on the basic material and formed via decarburizing, and a nitride compound layer formed on the decarburized layer and formed via nitriding of a nitride. A method of manufacturing a brake disk includes preparing a disk formed of gray cast iron, performing heat treatment of the disk to form a pre-decarburized layer and a base layer of gray cast iron over which the pre-decarburized layer is formed, and nitriding a portion of the pre-decarburized layer to form a nitride compound layer including a nitride and a decarburized layer over which the nitride compound layer is formed.

Abstract: A pinhole determination method for a fuel cell includes steps of blocking air supply to a fuel cell stack by a controller; measuring a cell voltage value of each of unit fuel cells of the fuel cell stack; and determining whether or not a pinhole is present by comparing the cell voltage value with an average cell voltage value.

Abstract: Disclosed are a deterioration estimation system for the fuel cell, a hydrogen supply system for a fuel cell including the same, and a hydrogen supply method for a fuel cell, the deterioration estimation system including a fuel cell which receives hydrogen gas and oxidizing gas respectively supplied to an anode side and a cathode side thereof to generate electrical power, a hydrogen supply line which is connected to the anode side of the fuel cell and supplies gas containing hydrogen gas to the fuel cell, a hydrogen supply valve which is located between the hydrogen supply line and a hydrogen tank, supplies, when opened, hydrogen gas stored in the hydrogen tank to the hydrogen supply line, and blocks the supply of the hydrogen gas when closed, and a deterioration estimating unit which estimates the deterioration state of the fuel cell, based on the opening and closing control of the hydrogen supply valve or a change in the pressure in the hydrogen supply line.

Abstract: Disclosed is a system for determining a hydrogen supply failure of a fuel cell, the system including: a fuel cell, a plurality of hydrogen tanks having hydrogen, a hydrogen supply line connected to the hydrogen tanks and supplying hydrogen from the hydrogen tanks to the fuel cell, a plurality of tank valves mounted on the hydrogen tanks, respectively, and discharging hydrogen in the hydrogen tanks to the hydrogen supply line when opening, a pressure sensor sensing pressure in the hydrogen supply line, and a determiner determining poor opening of the hydrogen tanks on the basis of pressure information sensed by the pressure sensor.

Abstract: A composition of a copper alloy for a laser cladding valve sheet is disclosed. The copper alloy includes a matrix structure and a hard phase, which includes 12 to 24 wt % of Ni, 2 to 4 wt % of Si, 8 to 30 wt % of Fe, more than 5 wt % and less than 10 wt % of Mo, 2 to 10 wt % of Al, and the balance Cu. The interfacial delamination may be suppressed in a fatigue environment by micronizing the hard phase and the distribution thereof, thereby improving fatigue resistance and wear resistance.

Abstract: A method of estimating hydrogen crossover loss of a fuel cell system including a stack for producing power through a reaction of hydrogen serving as fuel and air serving as an oxidizer includes driving the fuel cell system; estimating a hydrogen crossover rate right after a channel of an anode is purged; determining whether a cell voltage of a fuel cell is normal; and comparing the estimated hydrogen crossover rate with a predetermined reference value based on a result of the determining of whether the cell voltage of the fuel cell is normal to determine whether a pinhole or leakage occurs. Accordingly, whether a pinhole or leakage occurs in the fuel cell system may be more effectively sensed.