Abstract: A method is disclosed of detecting a failed link in a network over which nodes are interconnected via links. The nodes include an observer node and a managed node. This method, implemented for the observer node, includes: determining, for each of prefixes in receive route-update messages, a single normal-state path; determining, for each of the links (i.e.

Abstract: The present invention provides a BGP route evaluation device and method. A message receiving section 101 receives a BGP Update message. A status detecting section 102 detects the active/inactive status of each BGP route on the basis of a pair of prefix and next hop registered in “Announce” and “Withdraw” of the BGP Update message. In a management table 104, the active/inactive status of each BGP route is managed. An update section 103 updates the registration contents of the management table 104 on the basis of the detection result of the active/inactive status. An evaluation section 105 evaluates each BGP route on the basis of the registration contents of the management table 104.

Abstract: A method is disclosed of detecting a failed link in a network over which nodes are interconnected via links. The nodes include an observer node and a managed node. This method, implemented for the observer node, includes: determining, for each of prefixes in receive route-update messages, a single normal-state path; determining, for each of the links (i.e.

Abstract: The present invention provides a BGP route evaluation device and method. A message receiving section 101 receives a BGP Update message. A status detecting section 102 detects the active/inactive status of each BGP route on the basis of a pair of prefix and next hop registered in “Announce” and “Withdraw” of the BGP Update message. In a management table 104, the active/inactive status of each BGP route is managed. An update section 103 updates the registration contents of the management table 104 on the basis of the detection result of the active/inactive status. An evaluation section 105 evaluates each BGP route on the basis of the registration contents of the management table 104.

Abstract: A method of operating a laser is disclosed which includes irradiating an optical component in an atmosphere of dry air or dry inert gas with a laser beam, wherein the optical component is provided with an antireflection film having at least a layer of calcogenide glass and a layer of potassium chloride or lead fluoride.

Abstract: An antireflection film composed of a layer of arsenic triselenide having an optical thickness in the range between 2.518 and 2.783 .mu.m, a layer of potassium chloride having an optical thickness in the range between 1.151 and 1.272 .mu.m and a layer of arsenic triselenide having an optical thickness in the range between 0.577 and 0.749 .mu.m which are successively formed on a member of infrared radiation transmitting material formed of a mixture of thalium iodide and thalium bromide. The member provided with the three-layer antireflection film is used in an atmosphere of protective gas, such as dry air or dry N.sub.2 gas.

Abstract: An optical fiber which is able to transmit high power infrared energy, and is flexible and long in life is described. The fiber consists essentially of a mixed crystal of 40 to 45 wt % of thallium bromide and the balance of thallium iodide, each having a purity not less than 99.9%. The fiber is free of any particles having a size not smaller than 1 .mu.m.

Abstract: An image display device comprises first and second polarizers having their planes of polarizations oriented at right angles to each other and an electrooptic plate of ferroelectric ceramic material interposed between the first and second polarizers. A matrix electrode arrangement is secured to one surface of the ceramic plate to cause crystallographic structural changes to occur under the influence of a locally generated electric field, so that light passing through the first polarizer is refracted by an amount proportional to the magnitude of the electric field and emerges from the second polarizer with an intensity proportional to the electric field. The electrode arrangement includes a plurality of row electrodes and a plurality of column electrodes to define a plurality of elemental picture areas.

Abstract: A method of thermoluminescent dosimetry employing infrared radiation heating of a dosimeter. An incandescent lamp is used for the source of infrared radiation. The dosimeter is provided with a infrared radiation absorbing layer connected thermally to a thermoluminescent material layer. The infrared radiation absorbing layer is irradiated with infrared radiation, so that thermoluminescent material is not directly irradiated. The lamp is initially powered whereby the dosimeter is heated by infrared radiation of such high intensity as to tend to cause a heat equilibrium in the dosimeter above the temperature where thermal radiation is generated from the dosimeter. Then the power supplied to the lamp is cut or decreased, so that the dosimeter is heated by the afterglow of the lamp. Therefore the rate of temperature rise of the dosimeter becomes quite slow in the latter half of heating process, whereby the temperature of dosimeter easily falls into the required range.