Abstract: In a construction machine, an equipment room cover is formed with a maintenance hole, which has such a shape as to allow an air filter to pass, at a position on a rear side of the air filter mounted to a filter mounting portion of an air intake duct. A locking device of the filter mounting portion has a movable member movable between a locking position and a lock-releasing position. In the locking position, the movable member contacts with a rear surface of the air filter in a state that a front surface of the air filter is contacted with a contact member so that the air filter is sandwiched and held between the movable member and the contact member. In the lock-releasing position, the movable member is moved away from the rear surface of the air filter for allowing movement of the air filter toward the rear side.

Abstract: A network card, having a host connector and a network connector, comprises receiving means for receiving data transmitted through the network connector by block data of a second size larger than a first size as a unit through the host connector, a buffer memory for temporarily storing the received block data, and transmitting means for generating a data frame of not more than the first size and transmitting the data frame over a network connected to the network connector.

Abstract: In a microcomputer comprising internal buses, a serial communication interface, a flash memory, a RAM, a ROM for storing a writing program, an input/output port, a CPU, and a mode control unit for setting various operation modes and test modes in the microcomputer, a switching circuit is connected between the ROM and the internal buses and between the input/output port and the internal buses. The mode control unit operates the switching circuit in an emulation test mode so that the ROM is deactivated and the input/output port is activated. Then, the CPU reads a program from the serial communication interface and writes the program into the flash memory in accordance with a writing program from the input/output port.

Abstract: An optical fiber which has a cladding made of a cured material of a photosetting resin composition comprising at least one compound which has at least two unsaturated bonds in a molecule and a photopolymerization initiator, no compound which has only one unsaturated bond in a molecule being present in the composition, has excellent mechanical properties.

Abstract: An optical fiber which comprises a core made of a glass material, a thin plastic cladding formed on the peripheral surface of the core and a plastic coating formed on the plastic cladding, and satisfies the conditions (1) a specific refractive index of cladding resin after curing being 0.970 to 0.985 times that of the core periphery at a practical wavelength at ambient temperature, (2) light transmission through the cladding resin after curing being 500 to 4000 dB/km at a practical wavelength, and (3) a coefficient of linear expansion of the cladding resin after curing being not larger than 2.0.times.10.sup.-4 /.degree.C., which optical fiber has a wide band-width and high NA.

Abstract: An optical connector ferrule for positioning and securing an optical fiber such that the optical fiber is joined with a mating optical fiber; the optical fiber connector ferrule being provided with an insert portion having an end face; the insert portion having an outside diameter D and being formed with a bore for positioning the optical fiber; the bore having a diameter d; wherein a slot having a depth c of 0.005 to 0.