摘要:
In a bus type LAN, the data transmitted from a terminal (14) is detected by an adapter (1) connected to one end of a bus (3), and in response thereto the adapter (1) transmits a pulse signal onto the bus (3). An adapter (2) connected to the other end of the bus (3) receives the data transmitted from the terminal (14) and detects its source terminal address. A difference in time between the arrival of the data from the terminal (14) and the arrival of the pulse signal from the adapter (1) is measured by a counter circuit (21), and the count value obtained is stored in a memory (23), forming a pair with the corresponding source terminal address. Thus, the count value can be obtained for each terminal during the normal operation of the LAN. The data of the memory (23) are extracted by a personal computer (5), where the physical position of each terminal is calculated in accordance with the bus propagation velocity, and is displayed or printed out as a physical constitution diagram. Also, the packet signal, its collision signal, the jam signal and the pulse signal are utilized to measure the difference in time for the arrival of the pulse signal and so forth, to thereby specify the terminal having caused the packet collision.
摘要:
A composite electric cable including a plurality of element wires twisted together. The element wires include a material wire formed of a composite material containing an aluminum material and carbon nanotubes dispersed in the aluminum material; the material wire has a cellulation structure including a wall portion containing the carbon nanotubes and an inside portion of the wall which is surrounded by the wall portion and which comprises the aluminum material and unavoidable impurities; the material wire has a ratio of carbon nanotube content to aluminum material content of 0.2 wt. % to 5 wt. %; and each of all the element wires forming the composite electric cable is the material wire, or the composite electric cable includes in a center portion thereof one or a plurality of steel wires.
摘要:
A composite electric cable including a plurality of element wires twisted together. The element wires include a material wire formed of a composite material containing an aluminum material and carbon nanotubes dispersed in the aluminum material; the material wire has a cellulation structure including a wall portion containing the carbon nanotubes and an inside portion of the wall which is surrounded by the wall portion and which comprises the aluminum material and unavoidable impurities; the material wire has a ratio of carbon nanotube content to aluminum material content of 0.2 wt. % to 5 wt. %; and each of all the element wires forming the composite electric cable is the material wire, or the composite electric cable includes in a center portion thereof one or a plurality of steel wires.
摘要:
A vertical cavity surface emitting laser (VCSEL) device includes a pair of diffusion Bragg reflectors (DBRs) sandwiching therebetween a multiple quantum well (MQW) comprising active layers. The bottom DBR includes a lower layer structure having AlAs layers having a higher thermal conductivity and AlGaAs layers in pair and an upper layer structure acting anti-oxidation layers and having a pair of AlGaAs layers having different Al contents. A selectively oxidized AlAs layer disposed as the top layer of the bottom DBR comprises an Al-oxidized area and a non-oxidized layer for confinement of current injection path.