Abstract: Iron carbide is produced by an apparatus comprising first fluidized bed reactor 4 and second fluidized bed reactor 5, wherein the charged grainy iron oxide is reduced and carburized by the high temperature and high pressure gas being introduced from the bottom of the reactor. Both fluidized bed reactors comprise chamber 23 for introducing gas into the reactor, distribution plate 27 having multiple gas-introducing nozzles 28, partition plate 26 partitioning the fluidized bed into plural division rooms, and gas supply inlet 25a, 25b arranged on chamber 23 for supplying gas to specific division room respectively. Each gas supply inlet is connected to gas supply line having a gas flow control valve for controlling gas pressure or gas flow rate.

Abstract: A system is provided which manages the copyright of a plurality of data in a database. A data copyright management system is provided in which a primary user edits data which he or she obtains and supplies edited data to a secondary user. In a case where new data is produced by editing a plurality of encrypted data obtained from the database, and is encrypted for distribution to another person, crypt keys for a plurality of data as raw material and an edit program which is an editing process with a digital signature are used as a use permit key. The system comprises a database and a key control center, and uses a primary copyright label, a first use permit key including a first crypt key, a second use permit key, a third crypt key, and a copyright management program. The primary user uses primary copyrighted data encrypted using the first crypt key, by decrypting it with the first use permit key obtained from the key control center.

Abstract: A system is provided which manages the copyright of a plurality of data in a database. A data copyright management system is provided in which a primary user edits data which he or she obtains and supplies edited data to a secondary user. In a case where new data is produced by editing a plurality of encrypted data obtained from the database, and is encrypted for distribution to another person, crypt keys for a plurality of data as raw material and an edit program which is an editing process with a digital signature are used as a use permit key. When a user who receives the edited and encrypted data requests use of the data by presenting the digital signature to a copyright management center, the copyright management center identifies the editor by the digital signature, and provides the user requiring use of data with the crypt key for use only when the editor is identified to be the valid user of the edited data.

Abstract: A data copyright management system comprises a database for storing original data, a key control center for managing crypt keys, copyright management center for managing data copyrights, and a communication network for connecting these sections. Data supplied from the database to users is encrypted and distributed. The users decrypts the encrypted data by crypt keys obtained from the key control center or copyright management center. To supply data to users, there are the following two methods: a one-way supplying of encrypted data to users by means of broadcasting or the like; and two-way supplying of encrypted data to users corresponding to users' requests. A crypt key system used for encrypting data uses a secret-key cryptosystem, a public-key cryptosystem or a cryptosystem combining a secret-key and a public-key and further uses a copyright control program to control data copyrights.

Abstract: A data copyright management apparatus for handling data copyrights, and data of digital cash and video conference system is provided. The data copyright management apparatus comprises a CPU, ROM, EEPROM, and RAM. The ROM, EEPROM, and RAM are connected to the CPU bus, and a system bus of a device which utilizes the data can be connected to the CPU bus. A data copyright management system program, cryptographic algorithm, and user information are stored in the ROM, and a first public-key, a first private-key, a second public-key, a second private-key, a first secret-key, a second secret-key, and copyright information are stored in the EEPROM. The data copyright management apparatus may be configured in the form of a monolithic or hybrid IC, a thin IC card, PC card, insertion board, and further, may be incorporated in a computer, television set, set-top box, digital video tape recorder, digital video disk recorder, digital audio tape apparatus, or personal digital assistants, and the like.

Abstract: A data copyright management apparatus for handling data copyrights, and data of digital cash and video conference system is provided. The data copyright management apparatus comprises a CPU, ROM, EEPROM, and RAM. The ROM, EEPROM, and RAM are connected to the CPU bus, and a system bus of a device which utilizes the data can be connected to the CPU bus. A data copyright management system program, cryptographic algorithm, and user information are stored in the ROM, and a first public-key, a first private-key, a second public-key, a second private-key, a first secret-key, a second secret-key, and copyright information are stored in the EEPROM. The data copyright management apparatus may be configured in the form of a monolithic or hybrid IC, a thin IC card, PC card, insertion board, and further, may be incorporated in a computer, television set, set-top box, digital video tape recorder, digital video disk recorder, digital audio tape apparatus, or personal digital assistants, and the like.

Abstract: There are provided a digital content management apparatus which further embodies a digital content management apparatus used with a user terminal, and a system which protects the secrets of a digital content. The system and the apparatus are a real time operating system using a microkernel, which is incorporated in the digital content management apparatus as an interruption process having high priority. When a user uses the digital content, whether there is an illegitimate usage or not, is watched by interrupting the usage process. In the case where illegitimate usage is carried out, a warning is given or the usage is stopped. The decryption/re-encryption functions of the digital content management apparatus having the decryption/re-encryption functions are not restricted to the inside of the user apparatus. By providing the decryption/re-encryption functions between the networks, the exchange of secret information between different networks is secured.

Abstract: Provided is a method for producing iron carbide in which free carbon is generated with difficulty. When iron carbide is produced by reducing and carburizing iron-containing raw materials for iron making using a reaction gas mainly containing hydrogen and methane, steam or carbon dioxide is added into fluidized bed reactor (1) through line (7) in addition to the reaction gas supplied from line (2) into reactor (1) corresponding to a quantity of free carbon generated in reactor (1) which is obtained by means of dust meter (9). Consequently, the generation of the free carbon can be controlled.

Abstract: A data copyright management apparatus for handling data copyrights, and data of digital cash and video conference system is provided. The data copyright management apparatus comprises a CPU, ROM, EEPROM, and RAM. The ROM, EEPROM, and RAM are connected to the CPU bus, and a system bus of a device which utilizes the data can be connected to the CPU bus. A data copyright management system program, crypt algorithm, and user information are stored in the ROM, and a first public-key, a first private-key, a second public-key, a second private-key, a first secret-key, a second secret-key, a copyright information are stored in the EEPROM. The data copyright management apparatus may be configured in the form of a monolithic or hybrid IC, a thin IC card, PC card, insertion board, and further, may be incorporated in a computer, television set, set-top box, digital video tape recorder, digital video disk recorder, digital audio tape apparatus, or personal digital assistants, and the like.

Abstract: To prevent piracy or leakage of data content, a cryptography technique and electronic watermark technique are combined together and used. In a data content supplied to a user, a user data is entered as electronic watermark by a data management center, and the data content with an electronic watermark entered in it is encrypted using a crypt key and is supplied. The encrypted data content is decrypted using a crypt key distributed from the data management center and is used. In case it is to be stored, it is encrypted using another crypt key. In case the data content is copied and transferred to other user, a user data of the other user is entered as electronic watermark, and a scenario to enter the user data of the other user as electronic watermark is registered at the data management center, and the data content with electronic watermark entered in it is encrypted using another crypt key and is supplied.

Abstract: There are provided a digital content management apparatus which further embodies a digital content management apparatus used with a user terminal, and a system which protects the secrets of a digital content. The system and the apparatus are a real time operating system using a micro-kernel, which is incorporated in the digital content management apparatus as an interruption process having high priority. When a user uses the digital content, whether there is an illegitimate usage or not, is watched by interrupting the usage process. In the case where illegitimate usage is carried out, a warning is given or the usage is stopped. The decryption/re-encryption functions of the digital content management apparatus having the decryption/re-encryption functions are not restricted to the inside of the user apparatus. By providing the decryption/re-encryption functions between the networks, the exchange of secret information between different networks is secured.

Abstract: The present invention provides a system to ensure security of data in a computer network system. A center certifies a public-key of user of the system and distributes a secret-key. A first system comprises the center in a network, an information provider and a plurality of users. The center identifies utilization status by requests of the secret-key. The data is encrypted by the secret-key and is stored and transferred, while the data to be stored and transferred is encrypted by a secret-key different from the secret-key of the transferred data. An original data label is added to the original data, and an edit label is added to the edited data, and the center does not store the data and stores only the original data label and the edit label. A second system comprises a center and an information provider in a network, and a plurality of users utilizing the network. The center stores the original data and editing scenario, and also the original data label, user label and edit label.

Abstract: The present invention provides a method for controlling copyrights of digital data in a database system including real time transmission of a digital picture. Copyrights are controlled using one or more of the following, as necessary, in addition to a permit key: a copyright control program, copyright information or copyright control message. The copyright control program, the copyright information and the copyright control message are supplied together with the permit key, or they are supplied together with the data. Otherwise, a part of them is supplied together with the permit key and the other part of them is supplied together with the data. The data, the permit key, the copyright control message, the copyright information and the copyright control program are (1) transmitted while encrypted, but are decrypted when used, or (2) they are transmitted while encrypted and decrypted for display only, otherwise remaining encrypted, or (3) they may not be encrypted at all.

Abstract: A data copyright management system is provided, in which a primary user edits a received data and supplies the edited data to a secondary user. The copyright management system comprises a database and a key control center, and uses a primary copyright label, a primary use permit key including a first crypt key, a secondary use permit key, a third crypt key, and a copyright management program. The primary user decrypts the copyrighted primary data, which is encrypted using the first crypt key and supplied, to plaintext using a primary use permit key obtained from the key control center and utilizes it. If the copyrighted primary data is stored in a primary user device, it is re-encrypted using the primary use permit key. The primary user receives a secondary use permit key for editing the copyrighted primary data from the key control center and edits the copyrighted primary data. The data being edited is encrypted using the secondary use permit key and is stored.

Abstract: Provided is a file storing-and-managing method and device, for receiving, storing and managing electronic files over the Internet, the method and device including an effective and easy-to-operate GUI which can be operated visually and intuitionally without causing any stress. The file-managing device sends a graphical operation page to a user-computer connected over the Internet. The operation page includes a description (5) of the structure showing how the received-files are stored in the file-managing device and a description (7) of the structure showing how local files are stored in the user-computer, so that a user can easily upload and download files through graphical and intuitional operations of this page. Further, the file-managing device creates preview image data which is provided for previewing of the received-file and which has a data-size smaller than the original received-file. This preview image data is associated to and managed with the original received-file.

Abstract: A system is provided which manages the copyright of a plurality of data in a database. A data copyright management system is provided in which a primary user edits data which he or she obtains and supplies edited data to a secondary user. In a case where new data is produced by editing a plurality of encrypted data obtained from the database, and is encrypted for distribution to another person, crypt keys for a plurality of data as raw material and an edit program which is an editing process with a digital signature are used as a use permit key. When a user who receives the edited and encrypted data requests use of the data by presenting the digital signature to a copyright management center, the copyright management center identifies the editor by the digital signature, and provides the user requiring use of data with the crypt key for use only when the editor is identified to be the valid user of the edited data.

Abstract: A data copyright management apparatus for handling data copyrights, and data of digital cash and video conference system is provided. The data copyright management apparatus comprises a CPU, ROM, EEPROM, and RAM. The ROM, EEPROM, and RAM are connected to the CPU bus, and a system bus of a device which utilizes the data can be connected to the CPU bus. A data copyright management system program, cryptographic algorithm, and user information are stored in the ROM, and a first public-key, a first private-key, a second public-key, a second private-key, a first secret-key, a second secret-key, and copyright information are stored in the EEPROM. The data copyright management apparatus may be configured in the form of a monolithic or hybrid IC, a thin IC card, PC card, insertion board, and further, may be incorporated in a computer, television set, set-top box, digital video tape recorder, digital video disk recorder, digital audio tape apparatus, or personal digital assistants, and the like.

Abstract: Provided is a method for managing an operation of a producing process for obtaining an iron carbide product having a goal composition in a two-stages reaction process. A first-stage reaction process for partially reducing an iron-containing material for iron making is carried out, and a second-stage reaction process for performing further reduction and carburization is then carried out. A solid sample is taken at an outlet of a reactor for the first-stage reaction process to measure a reduction ratio of the solid sample. By regulating a parameter capable of changing a reduction ratio of the first-stage reaction process, an IC ratio obtained after the second-stage reaction process can be adjusted.

Abstract: A system is provided which manages the copyright of a plurality of data in a database. A data copyright management system is provided in which a primary user edits data which he or she obtains and supplies edited data to a secondary user. In a case where new data is produced by editing a plurality of encrypted data obtained from the database, and is encrypted for distribution to another person, crypt keys for a plurality of data as raw material and an edit program which is an editing process with a digital signature are used as a use permit key. When a user who receives the edited and encrypted data requests use of the data by presenting the digital signature to a copyright management center, the copyright management center identifies the editor by the digital signature, and provides the user requiring use of data with the crypt key for use only when the editor is identified to be the valid user of the edited data.

Abstract: A medical tube made of an organic polymer having a mechanical loss tangent of at least 0.5 at body temperature and a modulus of transverse elasticity of 1-1000 MPa at body temperature. The medical tube of the present invention can be easily inserted into the body, and gives less pain and less feeling of physical disorder during indwelling in the body or removal from the body.