Abstract: A mattress core material includes a plurality of flat cushion bodies stacked in a thickness direction thereof, including at least a first cushion body which becomes an upper part when using the mattress core material; and a second cushion body which becomes a lower part when using the mattress core material, the first and second cushion bodies including a three-dimensional filaments-linked structure, the first and second cushion bodies each including a high-density upper surface layer having high filament density, formed in an upper surface layer region; a high-density lower surface layer having high filament density, formed in a lower surface layer region; and a low-density elastic layer formed between the high-density upper surface layer and the high-density lower surface layer, the low-density elastic layer being lower in filament density than each high-density surface layer, a intermediate position in the thickness direction of the mattress core material in which the first and second cushion bodies are st

Abstract: A mattress core material includes a plurality of flat cushion bodies stacked in a thickness direction thereof, including at least a first cushion body which becomes an upper part; and a second cushion body which becomes a lower part, the first and second cushion bodies including a three-dimensional filaments-linked structure, each including a high-density upper surface layer having high filament density; a high-density lower surface layer having high filament density; and a low-density elastic layer, a high-density intermediate layer being formed in an intermediate position in the thickness direction of the mattress core material in which the first and second cushion bodies are stacked as upper and lower parts in the thickness direction, respectively, the high-density intermediate layer having a function of distributing a vertically applied compressive stress, along a curvature of an interface between the first and second cushion bodies in the high-density intermediate layer.

Abstract: A fault point location system comprises substation 1 installed along transmission and distribution line (TD line) to send a surge detection time (SD time), and master station 2 locates fault points based on the information. Substation 1 stores and updates past voltage or current waveforms of the TD line, stores a surge recognition level L2 (higher than a noise level), and a surge waveform starting level L1 (set lower than level L2), determines as the SD time, in the case where the voltage or current of the TD line exceeds level L2, the time at which the voltage or current first exceeded level L1 after going back through the waveforms stored from the time at which the surge recognition level was exceeded, and sends the SD time to master station 2 via the communication network.

Abstract: A fault point location system comprising substations 1 to send information of transmission and distribution lines, and the master station 2 to locate fault points under the information. Substation 1 detects a surge detection time and the surge current polarity. Master 2 identifies a no-branch fault section under the polarity, and identifies the fault point under a difference among detection times of substations 1 at both ends of the section, and the section length.