Reliability of the OS-280M Optical Submarine Repeater

The development phase of the OS-280M optical submarine cable system is finished, and currently the mass production lines for the system are arranged so as to satisfy the specific performances and the reliability requirements for the TPC-3 system within its system life of 25 years. KDD developed the reliability assurance system of the repeater components, which began three years ago. In this paper, we will introduce the reliability design of the OS-280M system and will report on the reliability test results obtained until the present time. In conclusion, it will be demonstrated that all of repeater components, i.e., optical semiconductor devices, monolithic IC's, several kinds of optical devices, and conventional components could satisfy the reliability requirements for the OS-280M system.     

Reduction of high surge voltage on coiled optical fibre submarine cable

The induced high surge voltage caused by a sudden change of feed current on the long coiled optical fibre submarine cable has been measured. The reduction methods of the induced voltage have been examined and their effects are demonstrated.     

MAP kinase pathways as a route for regulatory mechanisms of IL-10 and IL-4 which inhibit COX-2 expression in human monocytes

Herein we describe a new test system to produce a standardized partial muscle-tendon junction (MTJ) stretch injury. In anesthetized rabbits the tibialis anterior (TA) muscle-tendon unit is unilaterally shortened using a custom designed clamp roller system. An angular displacement (average velocity of 450 degrees x s[-1]) is applied about the foot to plantarflex the ankle 90 degrees while the lower extremity is fixed. During ankle rotation the TA muscle is tetanically stimulated to generate an eccentric stretch injury at the MTJ. Forty-eight hours after injury, isometric torque deficit (injured/sham) was measured. Two groups of animals (N = 6 in each group) were tested with the only difference between the two groups being the initial tendon shortening. In Group 1 (tendon shortening = 1.2 cm. N = 6) the torque deficit was 36.7+/-5.9% (mean+/-SD). In Group 2 (tendon shortening = 1.5 cm. N = 6) the torque deficit was 58.7+/-7.4% (mean+/-SD). No order effect was suggested by the data (P = 0.6062), but the difference in torque deficit between the two groups was highly significant (P = 0.0001). For all tests in which the tendon was temporarily shortened before muscle stimulation and stretch (N = 12) there was a visible hematoma at the MTJ similar to the injury that is common in athletic injuries. Histological evaluation 48 h after injury revealed both fiber tearing and inflammation at the MTJ. In addition, there was focal fiber damage in the muscle belly for both groups. The damage and inflammatory process, however, were more severe in the group with greater initial tendon shortening.     

A 1.0-V 230-MHz column access embedded DRAM for portable MPEGapplications

This paper describes a 32-Mb embedded DRAM macro fabricated using 0.13-μm triple-well 4-level Cu embedded DRAM technology, which is suitable for portable equipment of MPEG applications. This macro can operate 230-MHz random column access even at 1.0-V power supply condition. The peak power consumption is suppressed to 198 mW in burst operation. The power-down standby mode, which suppresses the leakage current consumption of peripheral circuitry, is also prepared for portable equipment. With the collaboration of array circuit design and the fine Cu metallization technology, macro size of 18.9 mm² and cell efficiency of 51.3% are realized even with dual interface and triple test functions implemented     

Expression, subcellular localization, and cloning of the 130-kDa regulatory subunit of myosin phosphatase in porcine aortic endothelial cells

In endothelial cells in situ and in primary culture, immunoblot analysis revealed an expression of the 130-kDa subunit of myosin phosphatase, similar to the myosin phosphatase targeting subunit (MYPT) of smooth muscle. Screening of an endothelial cell cDNA library yielded a clone encoding an NH2-terminal fragment of 89.6 kDa, closely related to smooth muscle MYPT1. Two isoforms differing by a central insert of 56 residues were detected. In growing cells, MYPT1 was localized on stress fiber, but at confluence the localization pattern changed and MYPT1 was distributed close to the cell membrane and at cell-cell contacts. The membrane localization of MYPT1 suggested a target other than myosin and raised the possibility that MYPT1 may be involved in dephosphorylation of alternative substrate(s). These distinct mechanisms would also be dependent on the growth state of the endothelial cells, i.e., regulation of actin-myosin interactions in growing cells and an unknown function in cells at confluence.     

Optical-fibre unit for optical submarine cable

An optical-fibre unit with a strain-relaxing effect is proposed for realising a highly reliable optical-fibre submarine cable. The basic design of the new type of optical-fibre unit means that optical fibres are not subjected to the same strain as the fibre unit directly when the unit is elongated. The test result of the strain-relaxing effect of an experimental optical-fibre unit was about 0.2%, and optical fibres returned to the original position in the fibre unit after the tension was released.     

Optical Fiber Submarine Cable System Development at KDD

An optical fiber submarine cable system using longwavelength and single-mode optical fiber is expected to provide economical long-haul digital transmission. This paper describes the recent research and development on an optical fiber submarine cable system for international communication at the KDD Research and Development Laboratories. An experimental model including cable and repeaters has been designed and manufactured. An experimental repeater of 1.3 μm and 280 Mbits/s was laid at a depth of 1500 m and its fundamental performance was measured in November 1981. Test production of longlength cable having a single continuous length of 30 km became possible in the end of 1981. In early June 1982, the experimental system with a 50 km cable length and two repeaters operating at 300 Mbits/s and 1.3 μm wavelength was laid in a loop into the Sagami Bay from the KDD Ninomiya Submarine Cable Landing Station.     

50 km, two-repeaters sea trial of optical-fibre submarine cable system

The experimental optical-fibre submarine cable system with 50 km cable and two repeaters was successfully laid in early June 1982. Optical loss changes of the cable during laying were less than 0.003 dB/km. The experiment will be continued during two or three years to obtain data on the cable and the repeaters.     

A design and experimental results of the OS-280M optical submarine repeater circuits

This paper describes the design philosophy and the experimental results of the optical submarine repeater for the OS-280M optical fiber submarine cable system to be installed across the ocean. This repeater which employs the information rate of 280 Mbit/s, the optical wavelength of 1.3 μ, and is implemented with monolithic ICs, features high reliability, long repeater spans, and the supervisory systems. The test results show that the average optical output power is - 1.4 dBm for the mark density of 1/2, the minimum average power of the optical input for the BER 10 is about -38 dBm at the room temperature, and other specifications are also well satisfied.