Patent application number | Description | Published |
20100169656 | GROUP SIGNATURE SYSTEM, DEVICE, AND PROGRAM - A group signature system includes a group manager device, a signer device and a verifier device capable of communicating with each other, each device using a group signature scheme. The group manager device generates a group secret key, a group public key, a member secret key and a signer tracing information. The signer device generates an encrypted text data of the signer tracing information, and a zero-knowledge proof showing that the signer device knows the member secret key and the encrypted text data is correctly generated based on the signer tracing information. The signer device transmits, to the verifier device, a group signature composed of the encrypted text data and the zero knowledge proof, and the message. The verifier device verifies correctness of the group signature and transmits the verified result to the signer device. | 07-01-2010 |
20110060903 | GROUP SIGNATURE SYSTEM, APPARATUS AND STORAGE MEDIUM - A group signature system according to one embodiment of the present invention comprises a group administrator apparatus, signer apparatuses and a verifier apparatus which can communicate with one another. Here, in a group signature method used by the apparatuses, a multiplication cyclic group or a bilinear group in which an order is unknown as in RSA is not used at all, but a multiplication cyclic group gG of a prime order q is only used, and representation parts k | 03-10-2011 |
20130339726 | FILE SERVER APPARATUS AND FILE SERVER SYSTEM - According to one embodiment, a reception unit receives post-office box's encrypted data, which is obtained by encrypting the data by using a post-office box's public key, from the sending apparatus. A re-encryption key storage unit stores a re-encryption key used for re-encrypting the post-office box's encrypted data into recipient's encrypted data, which is obtained by encrypting the data using a recipient's public key that is different from the post-office box's public key. A re-encryption unit re-encrypts the received post-office box's encrypted data to the recipient's encrypted data using the re-encryption key stored in the re-encryption key storage unit. A transmission unit transmits the re-encrypted recipient's encrypted data to the receiving apparatus. | 12-19-2013 |
20140050318 | RE-ENCRYPTION KEY GENERATOR, RE-ENCRYPTION APPARATUS, AND PROGRAM - A re-encryption key generator according to an embodiment generates a re-encryption key required to re-encrypt, without decrypting, ciphertext data obtained by encrypting plaintext data by means of a first public key of a first user device to obtain re-encrypted text data which can be decrypted by a second private key of a second user device. The first storage device stores a first private key corresponding to the first public key. The second storage device stores a second public key corresponding to the second private key. The re-encryption key generation device generates the re-encryption key based on the first private key, the second public key, and the first random number. | 02-20-2014 |
20140161251 | KEY MANAGEMENT SYSTEM - According to one embodiment, a master key management device generates, by using a first secret key stored in a first storage unit and a third public key, a re-encryption key used to re-encrypt a second secret key which is stored in a second storage unit and which is encrypted with a first public key to the second secret key encrypted with the third public key. A key management server device receives the generated re-encryption key from the master key management device while the master key management device and the key management server device are connected to each other, and stores the received re-encryption key in a third storage unit. The master key management device and the key management server device are disconnected after the re-encryption key is stored in the third storage unit. | 06-12-2014 |
20140208117 | SERVER APPARATUS AND PROGRAM - A server apparatus according to an embodiment generates a random number on receiving from a user apparatus a notification showing that a re-encryption key should be updated, and calculates re-encryption key data on the basis of the re-encryption key stored and the random number generated. The server apparatus transmits the re-encryption key to the user apparatus and receives, from the user apparatus, the user private key not updated yet and re-encryption key updating data calculated from the re-encryption key data on the basis of the user private key updated. The server apparatus calculates the re-encryption key updated, on the basis of the re-encryption key updating data and the random number, and replaces the re-encryption key stored in the storage device with the updated re-encryption key. | 07-24-2014 |
Patent application number | Description | Published |
20110054965 | Power Plant Life Cycle Costing System and Power Plant Life Cycle Costing Method - The power plant life cycle costing system for costing a power plant life cycle according to the present invention includes a flow chart generation unit for generating a power plant system flow chart based on specifications and cost information of major components of the power plant stored in a major component specifications storage unit, and plant specifications input from a plant specifications input unit; a power plant planning unit for calculating and generating a power plant life cycle cost, a plant efficiency and an operation plan including a maintenance plan as optimization indexes of a power plant configuration based on information from the flow chart generation unit, specifications and cost information of auxiliary devices of the power plant stored in a piping and device specifications storage unit, and optimization conditions of a power plant configuration input by an optimizing method selection unit; and an optimized result output unit for outputting a calculated value and a planned result calculated and generated by the power plant planning unit. | 03-03-2011 |
20130192193 | Solar Assisted Combined Cycle Power Plant - Disclosed is a solar assisted combined cycle power plant having a compressor that pressurizes combustion air, a combustor that mixes and burns the combustion air and gas turbine fuel to generate a high-temperature combustion gas, a gas turbine that drives the compressor by using the combustion gas, an exhaust heat recovery steam generator that obtains steam from thermal energy of a gas exhausted from the gas turbine, and a steam turbine that is driven by using the steam obtained by the exhaust heat recovery steam generator. The solar assisted combined cycle power plant includes a solar collector to turn supplied water to warm water; a heat accumulator that stores pressurized hot water from the solar collector and the exhaust heat recovery steam generator; and a spray device that handles the pressurized hot water as spray water and sprays the spray water onto the air to be taken into the compressor. | 08-01-2013 |
20140033720 | Controller for Gas Turbine Power Plant - A controller for use in a gas turbine power plant includes a compressor that compresses combustion air; a water-atomization cooling apparatus that sprays water drops of atomized water supplied via a water-atomization flow-rate regulating valve over a flow of air drawn in the compressor; a combustor that mixes the compressed combustion air with fuel to thereby burn a fuel-air mixture and generate combustion gas at high temperature and performs combustion switching during operation; a turbine that uses the combustion gas to drive the compressor and a generator; the water-atomization flow-rate regulating valve that controls a flow rate of the atomized water; and a compressor inlet inner blade that controls a flow rate of air drawn in the compressor. The controller includes control means that calculates a fuel-air ratio correction command signal for compensating for reduction in a fuel-air ratio in the combustor occurring during the combustion switching. | 02-06-2014 |
Patent application number | Description | Published |
20140020383 | Solar Heat Steam Cycle System - An object of the present invention is to provide a solar heat steam cycle system capable of operating efficiently and stably in keeping with the status of collected or stored heat, and a control method for use with the system. | 01-23-2014 |
20140260254 | Steam Turbine Power Plant - A steam turbine power plant includes heat-source equipment that heats a low-temperature flow by applying a heat medium and thus generates a high-temperature flow, a steam generator using the high-temperature flow generated by the heat-source equipment, a steam turbine driven by the steam generated by the steam generator, an electric generator that converts rotational motive power of the steam turbine into electric power, a heat-medium controller that controls a supply rate of the heat medium supplied to the heat source equipment, a low-temperature flow controller that controls a supply rate of the low-temperature flow supplied to the heat-source equipment, a prediction device that predicts startup constraints of the steam turbine from control input variables of the controllers when the steam turbine is started, and a control input variables setter so as to prevent data predictions by the prediction device from exceeding limit values of startup constraints. | 09-18-2014 |
20140290249 | Steam Turbine Power Plant - Disclosed is a steam turbine power plant adapted to start operating safely even if prediction accuracy of its startup constraints cannot be obtained. The system calculates predictive values and current values of startup constraints of a steam turbine from process variables of plant physical quantities, next calculates in parallel both a first control input variable for a heat medium flow controller based on predictive values, and a second control input variable for a main steam control valve based on the current values, and while preferentially selecting the first control input variable, if the first control input variable is not calculated, selects the second control input variable instead. After the selection of at least one of the first and second control input variables, the system outputs an appropriate command value to the heat medium flow controller and the main steam control valve according to the kind of selected control input variable. | 10-02-2014 |
20140290250 | Steam Turbine Power Plant - Disclosed is a steam turbine power plant adapted to start operating very efficiently by highly accurate look-ahead control of a plurality of its startup constraints. The power plant includes a fundamental startup constraint prediction device | 10-02-2014 |
20140373540 | Start Control Unit for Steam Turbine Plant - A start control unit for a steam turbine plant, wherein inputting a measured value of a steam temperature fed to a steam turbine, a measured value or an estimated value of a rotor temperature of the steam turbine, and a measured value of a casing temperature of the steam turbine, and controlling a steam flow rate so as to increase the steam flow rate fed to the steam turbine when a difference between the steam temperature and the rotor temperature is smaller than a first regulated value and a difference between the rotor temperature and the casing temperature is a second regulated value or larger. | 12-25-2014 |
20150121872 | Steam Turbine Power Plant and Method for Activating Steam Turbine Power Plant - Providing a steam turbine power plant that can be safely activated at a high speed while maintaining thermal stress at a level equal to or lower than a limit in consideration of operational results of the plant, and a method for activating the steam turbine power plant. The steam turbine power plant includes a life consumption amount calculator | 05-07-2015 |
20150121874 | ACTIVATION CONTROL DEVICE - Provided is a steam turbine plant activation control device that can flexibly handle an initial state amount of a steam turbine plant and activate a steam turbine at a high speed. The activation control device | 05-07-2015 |
20150135712 | Activation Control Device - A steam turbine plant activation control device is provided, which generates an activation schedule that enables a reduction in a time period required for the activation of a steam turbine plant without complex calculation such as prediction and calculation of a temperature and calculation of thermal stress. The activation control device includes: a storage circuit for storing a correlation between an initial value of a state amount parameter and a plant operation amount which includes a control reference value related to a control target amount and time lengths of phases in a process of activating the steam turbine plant; an operation amount determination circuit for determining time lengths of phases and a control reference value based on the initial value of the state amount parameter and the correlation stored in the storage circuit; and an activation schedule circuit configured to generate activation schedules of the phases based on the phase time lengths and the control reference value, which are determined by the operation amount determination circuit, and generate an activation schedule for a time period from the start to the completion of the activation of the steam turbine plant by combining the activation schedules. | 05-21-2015 |
Patent application number | Description | Published |
20140305034 | ASH-FREE COAL PRODUCTION METHOD - Provided is an ash-free coal production method that can produce an ash-free coal efficiently with a higher solvent recovery rate. The ash-free coal production method includes an extraction step of mixing coal with a solvent to give a slurry and heating the slurry to extract a solvent-soluble coal component; a separation step of separating a solution containing the coal component from the slurry containing the extracted coal component; and an ash-free coal obtaining step of separating and recovering the solvent from the separated solution to give an ash-free coal. The ash-free coal obtaining step includes a pressure-reducing substep of reducing a pressure to a level lower than the solvent vapor pressure to evaporatively separate the solvent from the solution to thereby give a solid ash-free coal; and a heating substep of heating the solid ash-free coal to evaporatively separate a residual solvent from the ash-free coal. | 10-16-2014 |
20140325901 | ASH-FREE COAL PRODUCTION METHOD - Provided is an ash-free coal production method without the need to once re-liquefy and form an ash-free coal. The ash-free coal production method includes an extraction step of mixing coal with a solvent to prepare a slurry and heating the slurry to extract a solvent-soluble coal component; a separation step of separating a solution containing the solvent-soluble coal component from the slurry obtained from the extraction step; an ash-free coal obtaining step of evaporatively separating the solvent from the solution separated in the separation step to obtain an ash-free coal. The ash-free coal obtaining step in the production method is performed so that the solvent is evaporatively separated from the solution to give a liquid ash-free coal, and the liquid ash-free coal is brought into contact with a solidifier (e.g., water) to solidify into a predetermined shape. | 11-06-2014 |
20150013215 | SOLVENT SEPARATION METHOD - A method for separating solvent-containing water, which is generated in the process for producing an ashless coal, into a solvent and water readily without using any adsorbent or the like (a solvent separation method). The solvent separation method comprises: a solvent-containing water supply step of supplying the solvent-containing water into a pressure vessel for solvent separation purposes; and a temperature retention step of retaining the temperature of the solvent-containing water that has been supplied into the pressure vessel for solvent separation purposes at a predetermined temperature (e.g., 100 to 180 DEG C. inclusive). In the pressure vessel for solvent separation purposes, water in the liquid form moves downward and the solvent moves upward due to the difference between the density of water and the density of the solvent at the predetermined temperature. In this manner, the solvent-containing water can be separated into the solvent and water. | 01-15-2015 |