Abstract: A surface acoustic wave device includes a substrate, a first electrode and a second electrode formed on the substrate to extend along a first direction, wherein the first electrode and the second electrode are alternately disposed along the second direction, one end of the first electrode on one side of the first direction is aligned along the second direction, and one end of the second electrode on the other side of the first direction is aligned along the second direction, a temperature compensation film which covers the first electrode and the second electrode, a first additional film formed on the temperature compensation film to vertically overlap a partial region from the one end of the first electrode on the one side of the first direction, and a second additional film formed on the temperature compensation film to vertically overlap a partial region from the one end of the second electrode.

Abstract: A surface acoustic wave device includes a substrate, a first electrode and a second electrode formed on the substrate to extend along a first direction, wherein the first electrode and the second electrode are alternately disposed along the second direction, one end of the first electrode on one side of the first direction is aligned along the second direction, and one end of the second electrode on the other side of the first direction is aligned along the second direction, a temperature compensation film which covers the first electrode and the second electrode, a first additional film formed on the temperature compensation film to vertically overlap a partial region from the one end of the first electrode on the one side of the first direction, and a second additional film formed on the temperature compensation film to vertically overlap a partial region from the one end of the second electrode.

Abstract: A surface acoustic wave device includes: a substrate; an electrode disposed on the substrate in a first direction; a dummy bar disposed to be spaced apart from the electrode by a predetermined distance in the first direction; and an additional film formed on the dummy bar, wherein the electrode and the dummy bar are disposed in plurality in parallel in a second direction perpendicular to the first direction, and the dummy bars are alternately disposed on a left side or a right side of the electrode to be spaced apart from the electrode by the predetermined distance, and the additional film is formed on the predetermined distance between the electrode and the dummy bar and on the plurality of dummy bars.

Abstract: A hydraulic system for a construction machine having a pressure compensation valve is disclosed, which improves operability when a combined operation of a swing device and an attachment is performed.

Abstract: Disclosed are a travelling control device for a construction machine for travelling a long distance by adjusting only one of left and right travelling pedals and a control method thereof.

Abstract: A hydraulic system provided with a relief valve for a construction machine is disclosed, which can reduce a discharge flow rate of a hydraulic pump when a relief valve is operated.

Abstract: A hydraulic system for a construction machine having a pressure compensation valve is disclosed, which improves operability when a combined operation of a swing device and an attachment is performed.

Abstract: A drive control system for preventing a sudden slowdown of driving speed to reduce the shock felt by a driver, when compound-operating two-way driving and a work device in an excavator.

Abstract: Disclosed is a hydraulic system for controlling the degree of openness of an arm regeneration valve by driving an electronic proportional control valve during a combined operation of simultaneously operating an arm and a swing device.

Abstract: A hydraulic system for a construction machine is disclosed, which can prevent off-course travel of the machine when a combined operation of a traveling device and a working device such as a boom is performed.

Abstract: A drive control system for preventing a sudden slowdown of driving speed to reduce the shock felt by a driver, when compound-operating two-way driving and a work device in an excavator.

Abstract: Disclosed is a hydraulic pump for construction machinery for controlling to inhibit one-way driving when compound-operating two-way driving and work devices, such as a boom, to enhance operation efficiency.

Abstract: A method for compensating a flow rate at a neutral position of an operation lever of construction equipment is adapted so that when RPM of an engine becomes different, an actuator can be identically driven according to an operating amount of the operation lever.

Abstract: A method for compensating a flow rate at a neutral position of an operation lever of construction equipment is adapted so that when RPM of an engine becomes different, an actuator can be identically driven according to an operating amount of the operation lever.