Abstract: A plurality of tracks on an optical disk are optically read to obtain a signal containing a plurality of LOW segments. Each of the plurality of LOW segments should correspond to a certification pit. Accordingly, if the interval between LOW segment Xj and nth succeeding LOW segment Xj+n exceeds the length of one track, a defect pit that could be confused with a certification pit is judged as being present between two certification pits.

Abstract: An optical disc storing a copyrighted digital product has a data area in which N processed parts are provided in order to certify that the stored digital product is an original one. A BCA provided on the optical disc stores judgment criteria information as well as N pieces of physical feature information. The judgment criteria information includes a numeric value N being the total number of processed parts, and a numeric value M being an integer between 0 and N inclusive and representing the security level to be assured for the digital data stored. When a numeric value P being the total number of processed parts in a normal state exceeds the numeric value M, a reproduction device reproduces the optical disc. When the numeric value P falls short of the numeric value M, the reproduction device does not reproduce the optical disc.

Abstract: Provided is a process for producing sintered ore in which a small amount of a water-soluble compound (a sintering aid) is added to iron ore powder and, thereby, which product shows improved strength and no adverse influence as an ironmaking raw material either without any increase in content of an auxiliary material (CaO) serving as a binder. In production of sintered ore, an aqueous solution is added to iron ore powder and an auxiliary material, the iron ore powder and the auxiliary material are kneaded to form a mixture, and the mixture is granulated to form granules, wherein the aqueous solution contains a water-soluble compound reacting with the iron ore powder to form a reaction product having a melting point of 1200° C. or lower.

Abstract: An optical disc storing a copyrighted digital product has a data area in which N processed parts are provided in order to certify that the stored digital product is an original one. A BCA provided on the optical disc stores judgment criteria information as well as N pieces of physical feature information. The judgment criteria information includes a numeric value N being the total number of processed parts, and a numeric value M being an integer between 0 and N inclusive and representing the security level to be assured for the digital data stored. When a numeric value P being the total number of processed parts in a normal state exceeds the numeric value M, a reproduction device reproduces the optical disc. When the numeric value P falls short of the numeric value M, the reproduction device does not reproduce the optical disc.

Abstract: Disclosed herein are an inexpensive catalyst for removing nitrogen oxides effectively from an exhaust gas by either catalytic reduction or catalytic decomposition, and a process for removing nitrogen oxides from an exhaust gas by the aid of said catalyst. The invention will eliminate the disadvantages--high material cost and complex process for catalyst preparation--involved in the conventional technology. The catalyst contains as the major constituent a multiple oxide of the CaO--Fe.sub.x O type containing 5-50 wt % CaO, said catalyst reducing or decomposing nitrogen oxides. The process is designed for denitration of nitrogen oxides by the aid of said catalyst.

Abstract: Disclosed herein are an inexpensive catalyst for removing nitrogen oxides effectively from an exhaust gas by either catalytic reduction or catalytic decomposition, and a process for removing nitrogen oxides from an exhaust gas by the aid of said catalyst. The invention will eliminate the disadvantages--high material cost and complex process for catalyst preparation--involved in the conventional technology. The catalyst contains as the major constituent a multiple oxide of the CaO-Fe.sub.x O type containing 5-50 wt % CaO, said catalyst reducing or decomposing nitrogen oxides. The process is designed for denitration of nitrogen oxides by the aid of said catalyst.