Abstract: In communication cable of high capacity according to present invention, conductor of diameter d is coated by insulation material to form wire of diameter D, plural number of said wire are twisted by pitch p to form pairs, plural number of said pairs are twisted by collective pitch P, and said communication cable of high capacity comprise sheath wrapping said pairs, and impedance (Z) of said wire is from 90 to 110, and, diameter (d) of said conductor is from 0.48 mm to 0.65 mm, and diameter (D) of wire is from 0.8 mm to 1.15 mm, and said pitch (p) is from 7 mm to 30 mm, and said collective pitch (P) is from 40 mm to 150 mm, and relative ratio of diameter of wires to diameter of conductor D/d is from 1.625 to 1.835. And, by impedance matching between impedance of wire and impedance of equipment for data transmission, return loss of cable can be minimized, so high speed data transmission can be made.

Abstract: Disclosed are a composition for a cable-covering material used in railway vehicles, and a cable for railway vehicles using the same. The present invention provides the halogen-free flame retardant composition including 100 parts by weight of a base resin including ethylene-vinylacetate copolymers; 60 to 250 parts by weight of mixed metal hydroxide as a halogen-free flame; 1 to 30 parts by weight of a flame-retardance auxiliary; 0.5 to 5 parts by weight of a silane-based coupling agent; 0.5 to 8 parts by weight of a cross-linking formulation; and 3 to 15 parts by weight of a cross-linking agent. The composition according to the present invention may be used in the cable-covering material for railway vehicles under the extreme conditions because it has excellent properties such as resistance against dynamic pressure at high temperature and durability, as well as low smoke and flame retardance upon its combustion.

Abstract: Disclosed is a method for manufacturing a multimode optical fiber for high data rate LAN using MCVD, which includes a deposition process for forming a clad layer and a core layer, doped with an additive for controlling a refractive index, on an inner wall of a quartz tube by injecting a deposition gas into the quartz tube and applying heat to outside of the quartz tube; and a collapse process, which is repeatedly conducted N times, for filling up a gap in the quartz tube by applying heat of a temperature over a deposition temperature to the quartz tube after the core layer is completely deposited. In the method, together with an N?1th collapse process, an etching process of injecting a reaction gas for etching into the quartz tube is conducted in order to eliminate a portion of which refractive index is transformed due to evaporation of the additive.

Abstract: Disclosed are a flame retardant composition for a cable covering material and an ocean cable using the same. The flame retardant composition of the present invention includes 100 parts by weight of a base resin; 30˜150 parts by weight of a flame retardant; 1-30 parts by weight of a cold resistant plasticizer; 0.5˜10 parts by weight of a silane coupling agent; 0.5-8 parts by weight of a co-crosslinking agent; and 3-20 parts by weight of a crosslinking agent, and the ocean cable using the same. The composition for a cable covering material according to present invention has an excellent oil resistance to oil components without deteriorating mechanical properties, and has a superior durability such as a cold resistance at ?40° C. as well as minimally generates toxic gases upon firing and has an excellent flame retardancy.

Abstract: In communication cable of high capacity according to present invention, conductor of diameter d is coated by insulation material to form wire of diameter D, plural number of said wire are twisted by pitch p to form pairs, plural number of said pairs are twisted by collective pitch P, and said communication cable of high capacity comprise sheath wrapping said pairs, and the diameter d of said conductor and diameter D of said wire and pitch p and collective pitch P and impedance of said wires are defined by function of compensation coefficient A (81<A<83) by dielectric constant of insulation member and magnetic permeability of conductor, compensation coefficient B (0.005<B<0.007) by pitch (p) and collective pitch (P). And, by impedance matching between impedance of wire and impedance of equipment for data transmission, return loss of cable can be minimized, so high speed data transmission can be made.

Abstract: Disclosed is an air blown optical fiber unit having beads attached on its surface. The air blown optical fiber unit includes at least one optical fiber, a buffer layer surrounding the optical fiber and made of polymer resin, an outer layer surrounding the buffer layer and made of polymer resin, and beads attached on a surface of the outer layer to have height of 40 ?m to 120 ?m on the average. This air blown optical fiber unit gives improved installation characteristics.

Abstract: Disclosed is a superconducting power cable capable of quench detection, and a quench detection system using the superconducting power cable. The superconducting power cable capable of quench detection includes a former; a superconducting conductor layer composed of a superconducting wire and surrounding the former; a conductor layer quench detection coil interposed between the former and the superconducting conductor layer and surrounding the former; an insulating layer surrounding the superconducting conductor layer; and a shielding layer surrounding the insulating layer. This superconducting power cable may detect quench generated during its operation in real time.

Abstract: An apparatus for monitoring an inside of a manhole in which the inside of the manhole is monitored using a simple communication and power supply unit is closed.

Abstract: The present invention relates to an optical fiber unit for air blown installation, which includes at least one optical fiber; a buffer layer surrounding the optical fiber and made of radiation curing acrylate; an outer layer surrounding the buffer layer and made of radiation curing acrylate; and a group of solid particles attached to a surface of the outer layer and having an average diameter of 80 to 140 ?m and a specific weight of 2 to 3 g/cc. Thus, there is provided a structurally stable optical fiber unit, which allows easy control of particles while the optical fiber unit is produced, and also has improved installation properties.

Abstract: Disclosed is a fiber reinforced plastic wire used as the overhead transmission cable. The fiber reinforced plastic wire for a strength member of an overhead transmission cable according to the present invention includes a wire having a predetermined diameter and composed of thermoset matrix resin; and a plurality of high strength fibers dispersed parallel to a longitudinal direction in an inside of the wire, the high strength fibers being surface-treated with a coupling agent to improve interfacial adhesion to the matrix resin. The fiber reinforced plastic wire of the present invention has the high tensile strength at the room temperature and the high temperature since its high strength fiber is surface-treated with a coupling agent. The fiber reinforced plastic wire can be also effectively used as the strength member in the overhead transmission cable since it has the excellent low coefficient of thermal expansion, etc. and is light-weight.

Abstract: Disclosed is an air blown optical fiber unit for reducing a micro-bending loss. The air blown optical fiber unit includes at least one optical fiber; a buffer layer surrounding the optical fiber and made of polymer resin having a Young's modulus of 0.05 to 2 kgf/mm; and an outer layer surrounding the buffer layer and having beads attached to a surface thereof, the outer layer being made of polymer resin, wherein the buffer layer has a thickness of 70 to 140 ?m. This optical fiber unit may reduce a micro-bending loss of an optical fiber by buffering an external force applied to the optical fiber due to beads attached to its surface.

Abstract: Disclosed is installation of an optical fiber composite electric power cable. An installation method of an optical fiber composite electric power cable includes installing an electric power cable including a conductor and an air-blown installation tube therein at an installation region; connecting tubes of adjacent electric power cables to each other, in an electric power cable connection box; and installing an optical fiber unit into the connected tubes by air pressure. Also, a cable structure used for installing the optical fiber composite electric power cable includes a conductor for electric power transmission; an insulator surrounding the conductor; an air-blown installation tube provided outside of the insulator; and a corrosion-protective layer provided to an outermost layer of the cable.

Abstract: A micro coaxial cable includes an inner conductor; an insulation layer having foaming cells and formed to surround the inner conductor; an over-foaming preventing layer formed to surround the insulation layer for the purpose of uniform forming of the foaming cells; a metal shield layer formed to surround the over-foaming preventing layer; and a protective coating layer formed to surround the metal shield layer.

Abstract: A method for manufacturing a single mode optical fiber with a reduced PMD (Polarization Mode Dispersion), by drawing an optical fiber preform composed of a core and a clad surrounding the core, includes (a) heating the optical fiber preform to a high temperature using a furnace, and drawing an optical fiber from an outlet of the furnace at a linear velocity (Vf) of 500 mpm or above by means of neck-down drawing; and (b) impressing a spin on the optical fiber by means of a spin impressing device provided on a drawing path of the optical fiber, wherein a maximum spatial frequency of spin (y) impressed on the optical fiber satisfies the following equations Exp ? ( 24 ? t - 12 ) ? y ? - 20 × log ( V f 500 ) + 25 and t=(0.21×CladOval)+(0.04×CoreOval)+(0.17×ECC), where y is a maximum spatial frequency of spin [turns/m], Vf is a drawing velocity [mpm], CladOval is a clad ovality [%], CoreOval is a core ovality [%], and ECC is an eccentricity [?m].

Abstract: A separator for a communication cable includes a plurality of barriers formed in a radial direction so that at least two pair units, in each of which at least two insulation-coated wires are spirally twisted, are received in spaces formed by the barriers one by one so as to separate the pair units from each other. At least one of the barriers has a relatively greater thickness than the other barriers. Thus, a communication cable having the separator may prevent PSNEXT (Power Sum Near and Crosstalk) caused by interference between adjacent wires when a high frequency signal is transmitted through the wires.

Abstract: Disclosed is a polypropylene resin composition with flame retardance and abrasion resistance. The polypropylene resin composition according to the present invention includes 20 to 200 parts by weight of an inorganic flame retardant; and 0.1 to 10 parts by weight of at least one additive, based on 100 parts by weight of a base resin comprising 30 to 90% by weight of polypropylene copolymer resin and 10 to 70% by weight of polyolefin alpha copolymer resin. The polypropylene resin composition according to the present invention can be used for industrial cables with potent endurance since it includes an inorganic flame retardant to show flame retardance and it can remove or reduce a whitening phenomenon and show a significantly improved abrasion resistance without deteriorating moldability or mechanical property even when the contents of the composition are varied to enhance abrasion resistance.

Abstract: A dicing die adhesive film for semiconductor of the present invention has a 3-layered structure including a first adhesive layer attached on the back of a semiconductor wafer; a second adhesive layer attached onto the first adhesive layer; and a dicing film attached onto the second adhesive layer, and therefore has an advantage that it can ensure reliability of the semiconductor packaging process since it may prevent the die-flying phenomenon and the poor pickup of the die in the dicing process and maintain a sufficient adhesive force between the die and the substrate upon die boding.

Abstract: Disclosed are a composition for a cable-covering material used in railway vehicles, and a cable for railway vehicles using the same. The present invention provides the halogen-free flame retardant composition including 100 parts by weight of a base resin including ethylene-vinylacetate copolymers; 60 to 250 parts by weight of mixed metal hydroxide as a halogen-free flame; 1 to 30 parts by weight of a flame-retardance auxiliary; 0.5 to 5 parts by weight of a silane-based coupling agent; 0.5 to 8 parts by weight of a cross-linking formulation; and 3 to 15 parts by weight of a cross-linking agent. The composition according to the present invention may be used in the cable-covering material for railway vehicles under the extreme conditions because it has excellent properties such as resistance against dynamic pressure at high temperature and durability, as well as low smoke and flame retardance upon its combustion.

Abstract: Disclosed is an optical fiber suitable for WDM system, particularly whose zero-dispersion wavelength is positioned in a short wavelength band less than 1,300 mm. In the optical fiber, dispersion has a positive value, not zero, at 1,310 nm, and a dispersion slope is positive at 1,550 nm with dispersion of 25 ps/nm-km or less. In addition, an effective sectional area is 65 ?m2 or less at 1,310 nm, and 80 ?m2 or less at 1,550 nm. Thus, though a transmission signal is Raman-amplified at a wavelength band of 1,300˜1,700 nm, transmission characteristics are not deteriorated due to crosstalk between pump signals. In addition, since the optical fiber has smaller effective sectional area than a general single-mode optical fiber with having substantially the same dispersion feature, it gives better Raman gain efficiency than a general single-mode optical fiber.

Abstract: A composition for manufacturing insulation materials of an electrical wire having a multilayer structure, which is used for manufacturing a first insulation coating layer made of a composition including a predetermined base resin, an antioxidant and a co-crosslinking agent so as to surround a conductor or a conductor bundle for an electrical wire; a second insulation coating layer made of a composition including a base resin polyvinylidene fluoride (PVDF), a predetermined antioxidant and a co-crosslinking agent so as to surround the first insulation coating layer, and an electrical wire manufactured using the same.