Abstract: According to one embodiment, a magnetic disk device includes a disk including a first region and a second region, a head configured to record write data to the disk, a buffer configured to store the write data up to a first capacity, and a controller configured to obtain a first processing amount based on a time to save the write data to the first region by the head and a second processing amount improved by saving the write data from the buffer to the first region, compare the first processing amount with the second processing amount, and determine whether the write data should be saved to the first region, based on a result of the comparison between the first processing amount and the second processing amount.

Abstract: According to one embodiment, a magnetic disk device includes a disk including a first region and a second region, a head configured to record write data to the disk, a buffer configured to store the write data up to a first capacity, and a controller configured to obtain a first processing amount based on a time to save the write data to the first region by the head and a second processing amount improved by saving the write data from the buffer to the first region, compare the first processing amount with the second processing amount, and determine whether the write data should be saved to the first region, based on a result of the comparison between the first processing amount and the second processing amount.

Abstract: A silica glass crucible 1 having &agr; of 0.05 or less over a thickness of 0.5 mm or more from the inner surface of the silica glass crucible, &agr; being obtained by dividing the fluorescent intensity integrated over a wavelength range of 4,000 cm−1 and 4,100 cm−1 by the fluorescent intensity integrated at a wavelength of 800 cm−1 where an SiO peak appears as determined by subjecting a section of the thickness of the silica glass crucible to laser Raman spectroscopy involving excitation by laser beam of 514 nm, and an OH group concentration of 100 ppm or less over the entire periphery beyond a thickness of at least 1.0 mm from the inner surface of the silica glass crucible.

Abstract: An optical disk apparatus in which a write cache processing is executed, comprising a writing function for writing test data to a predetermined area of the optical disk when no write data processing is provided, a checking function of reading test data to check whether the writing function is normal or abnormal, a function of performing the write cache processing in the case of the test writing being normal, and performing the ordinary writing processing in the case of the test writing being abnormal.

Abstract: A circuit such as a duplexer which isolates a first and second frequency signals respectively directed to and from an antenna terminal. A transmitter filter has a output terminal connected to a connecting point through a first inductor. A receiver filter has an input terminal connected to the connecting point. The connecting point is connected to the antenna terminal, and to ground through a second inductor. In a modified circuit the output terminal of the transmitter filter and the input terminal of the receiver filter are respectively connected to the connecting point through first and second capacitors. In the preferred embodiments the transmitter filter and the receiver filter are mounted to one side of a dielectric plate and the inductor and/or capacitors are formed by electrically conductive step lines and a capacitance patterns formed on the opposite side of the dielectric plate.

Abstract: A microwave filter comprising a rectangular ceramics block (30) having a plurality of elongated parallel holes (31-36) extending from the top surface to the bottom surface thereof. The holes are plated with conductive layers (37, 38), and flat conductive areas (39-44) coupled with the layers (37, 38) spatially disposed on the top surface of the dielectric block (30) surround opening ends of the holes (31-36). An input terminal and an output terminal are provided adjacent to the conductive areas (39, 44) at both the extreme sides of the dielectric block (30).