Nippon Telegraph and Telephone Corporation

Shinagawa Refractories Co., Ltd.

Akihiro Morita

Hideaki Kimura

Erina Takeshita

Kenji Ichikawa

Gou Yazawa

Osamu Nomura

Seiji Yoshida

Takashi Hirose

Youichi Fukada

Keisuke Nishi

Hideaki Fujiwara

Tomoaki Omoto

Ryosuke Nakamura

Hiroyuki Sugimoto

Go Yazawa

Koyo Yanagawa

Yukimasa Iwamoto

Yoichiro Kawabe

Shinji Hattori

An object of the present invention is to provide an edge device, a control method, and a program with which the effects of loop generation can be minimized from the NW operator side while ensuring connection normality with the device of an NW user. An edge device according to the present invention physically closes an access port upon confirmation that the access port has been connected to an external device while the access port is in a physically released state and a DF state is undefined, notifies other edge devices within an EVPN MH configuration that the host device has entered a state in which the host device may become the DF and causes an EVPN function unit to calculate the DF state to be set, physically opens the access port when the calculation result indicates DF, and physically closes the access port when the calculation result indicates BDF.

Edge device, control method, and program

Provided are a control apparatus, a control method, and a program capable of designing efficient end-to-end monitoring in a VPN infrastructure. The control apparatus according to the present invention controls end-to-end monitoring in a VPN infrastructure in which communications of a plurality of users are superimposed. The control apparatus includes a user end databasethat stores information about customer edge apparatuses (CEs) for each of the users, each of the CEs serving as a monitoring end of end-to-end monitoring, an end-to-end path databasethat stores information about all links included in a path between the CEs, and an end-to-end monitoring management unitthat sets a monitoring path for end-to-end monitoring to between the CEs so that combinations of the monitoring path passing through each of the links are coprime.

Control device, control methods and programs

A network device (PE), a network control method and program which can reduce a BUM traffic packet loss even when a time is taken for route recalculation according to a routing protocol due to a malfunction in a network infrastructure are provided. A network device according to the present invention requests each PE connected to the same ES as that of the network device to perform DF reelection on the basis of a redundant PE list from which the network device has been deleted when cease of a BGP session is detected. In addition, the PE requested to perform the DF reelection executes the DF reelection based on the redundant PE list from which the aforementioned PE has been deleted. In the present invention, BUM traffic can be immediately forwarded from a PE that has become a new DF even when a time is taken for route recalculation according to the routing protocol because another PE connected to the same ES is caused to serve as a DF when the BGP session is ceased.

Network device, network control method, and program

An object of the present disclosure is to provide a provider network device, a network system, and a program that shorten a communication disconnection time during redundancy switching in a Single-Active redundant configuration. The provider network device according to the present disclosure notifies a CE that a VLAN, which has been communicating with traffic, is disabled due to setting of a block point or that new traffic communication is enabled due to releasing of the block point. This allows the CE to quickly delete a previously used transfer database and build up a new transfer database, and thus it is possible to shorten a communication disconnection time during redundancy switching.

Common carrier network device, network system, and program

A time synchronization method that is capable of selecting whether synchronization, by a timepiece unit that generates a time signal synchronized with a standard time and outputs it to an exterior, with the time is performed by time information obtained by receiving a radio wave including information relating to the time, or is performed by means of a holdover performed using a clock signal from an internal or external clock source. A schedule having a first time period in which the above-mentioned time information is used, and a second time period by means of the holdover is determined according to temporal reception characteristics of the radio wave at a reception location of the radio wave, and according to the schedule, supplying the timepiece unit with the time information or supplying the timepiece unit with the clock signal from the internal or external clock source.

Time synchronization device, and method and program therefor

A satellite signal reception characteristic estimation apparatus includes a satellite orbital information collection unit that collects and outputs orbital information for a satellite; a peripheral environment spatial information collection unit that collects spatial information for a peripheral environment of an installation position of a satellite antenna; a positional information collection unit that collects and outputs positional information for the installation position of the satellite antenna; and a simulation server unit that estimates reception characteristics of satellite signals at the installation position of the satellite antenna by performing a simulation based on the orbital information, the spatial information, and the positional information outputted from the satellite orbital information collection unit, the peripheral environment spatial information collection unit, and the positional information collection unit.

Satellite signal reception characteristic estimation apparatus, method thereof, and program thereof

An object of the present invention is to provide a mold powder for continuous casting of steel whose fluorine content is small, and which enables stable casting, for reducing the corrosion of continuous casting equipment and decreasing the concentration of fluorine in the waste water, well as a method for continuous casting of steel using mold powder. The mold powder for continuous casting of steel of the present invention is characterized by having a chemical composition including 25 to 70 wt % of SiO , 10 to 50 wt % of CaO, not more than 20 wt % of MgO, and 0 to 2 wt % of F as an unavoidable impurity, where the viscosity of the molten mold powder is not less than 4 poise at 1,300&deg; C.

Molding powder for continuous casting of steel and method for continuous casting of steel

A mold powder characterized in that, a weight ratio of CaO to SiO,in the mold powder is within a range of 0.50 to 1.20, the mold powder contains one or two or more species selected from a group consisting of oxides, carbonates, or fluorides of alkali metals, alkaline earth metals, or other metals, and 0.5 to 5 percent by weight of carbon powder, Li,O content is within a range of 1 to 7 percent by weight, F content is within a range of 0.5 to 8.0 percent by weight, crystallization temperature is within a range of 1000 to 1200&deg; C., surface tension at 1300&deg; C. is 250 dyne/cm or more, and a relationship between viscosity &eegr; (poise) at 1300&deg; C. and casting speed V (m/min) satisfies a range represented by an expression 6.0&lE;&eegr;V&lE;100.0. By the present invention, there is provided a mold powder which enables stable casting by reducing the likelihood of powder entrapment into the mold without giving rise to surface crack when casting with a thin-slab continuous caster.

Molding powder for continuous casting of thin slab

Exothermic type mold additives for continuous casting

A mold additive suitable for use in a mold for continuous casting of steel which comprises, as its base material, at least 50% by weight of synthetic calcium silicate which contains CaO and SiO.sub.2 in a total amount not less than 70% by weight, and whose CaO/SiO.sub.2 ratio is not lower than 1.20. A mold additive of low bulk density and superior in heat insulation can be obtained and its CaO/SiO.sub.2 ratio can be widely adjusted.

Growing community of inventors

Tokyo, Japan

Akihiro Morita