Abstract: There are disclosed an improved method for production of a polarizing glass having a high extinction ratio by facilitating control of the diameter of silver halide particles in a mother glass with high Ag concentration, and a polarizing glass produced by the method. The glass is a polarizing glass having dispersed and oriented geometrically anisotropic metallic silver particles at least in its surface layer, which is characterized by not containing TiO2 exceeding 1.7 wt % but containing not less than 0.4 wt % Ag, and in that Ag and halogens contained therein satisfy the following relations: the molar ratio of Ag/(Cl+Br) is 0.2 to 1.0; the molar ratio of Cl/(Cl+Br+F) 0.5 to 0.95; and the molar ratio of Br/(Cl+Br+F) 0.05 to 0.4. The method for production comprises the steps of drawing a glass containing dispersed AgClxBr1-x crystals, and then reducing it under a reducing atmosphere.

Abstract: A method for controlling joint purchase reverse auction. The method first determines a contract price for a total procurement amount putting together purchase desires of a plurality of buyers according to a bid by at least one supplier. Then, it calculates a contract price of each buyer from the contract price for the total procurement amount at least according to a purchase scale of the buyer or a procurement price prior to reverse auction of the buyer.

Abstract: A reverse auction method implemented by a server connected to a plurality of buyer terminals and a plurality of supplier terminals through a network. The method selects desired purchase terms as candidates forjoint purchase from desired purchase terms received from the plurality of buyer terminals, and transmits an invitation to participate in joint purchase to a buyer terminal of a buyer corresponding to at least the selected desired purchase terms. Then, the method receives a participation response to the invitation from a buyer terminal of a buyer intending to participate in reverse auction and determining a combination of buyers participating in joint purchase according to the participation response.