We analyze product differentiation in a multi-dimensional model with non-uniform consumer distribution.The level of product differentiation is measured by both unit transport costs and firms'locations.Our analysis...We analyze product differentiation in a multi-dimensional model with non-uniform consumer distribution.The level of product differentiation is measured by both unit transport costs and firms'locations.Our analysis concerns both measures.First,fixing firms'locations,we show that equilibrium prices can increase or decrease with unit transport costs.The overall result depends on the interplay of a shifting effect and a rotating effect-the latter exists only in multi-dimensional models.Second,fixing unit transport costs,we find that under non-uniform distribution,there may exist no equilibrium where firms maximize differentiation on one dimension but minimize differentiation on other dimensions.Instead,there may exist an equilibrium where firms choose intermediate locations,contrary to common findings in existing studies which assume uniform distribution.展开更多
A Raman spectroscopy method combined with neural network is used for the invasive and rapid detection of echinococcosis. The Raman spectroscopy measurements are performed on two groups of blood serum samples,which are...A Raman spectroscopy method combined with neural network is used for the invasive and rapid detection of echinococcosis. The Raman spectroscopy measurements are performed on two groups of blood serum samples,which are from 28 echinococcosis patients and 38 healthy persons,respectively. The normalized Raman reflection spectra show that the reflectivity of the echinococcosis blood serum is higher than that of the normal human blood serum in the wavelength ranges of 101—175 nm and 1 801—2 701 nm. Then the principal component analysis(PCA) and back propagation neural network(BPNN) model are used to obtain the diagnosis results. The diagnosis rates for healthy persons and echinococcosis persons are 93.333 3% and 90.909 1%,respectively,so the average final diagnosis rate is 92.121 2%. The results demonstrate that the Raman spectroscopy analysis of blood serum combined with PCA-BPNN has considerable potential for the non-invasive and rapid detection of echinococcosis.展开更多
文摘We analyze product differentiation in a multi-dimensional model with non-uniform consumer distribution.The level of product differentiation is measured by both unit transport costs and firms'locations.Our analysis concerns both measures.First,fixing firms'locations,we show that equilibrium prices can increase or decrease with unit transport costs.The overall result depends on the interplay of a shifting effect and a rotating effect-the latter exists only in multi-dimensional models.Second,fixing unit transport costs,we find that under non-uniform distribution,there may exist no equilibrium where firms maximize differentiation on one dimension but minimize differentiation on other dimensions.Instead,there may exist an equilibrium where firms choose intermediate locations,contrary to common findings in existing studies which assume uniform distribution.
基金supported by the National Natural Science Foundation of China(No.61308120)the Doctor Startup Project of Xinjiang University(No.BS120122)+1 种基金the Young Talents Project in Xinjiang Uygur Autonomous Region(No.2013731003)the Xinjiang Science and Technology Project(Nos.201412107 and 2014211B003)
文摘A Raman spectroscopy method combined with neural network is used for the invasive and rapid detection of echinococcosis. The Raman spectroscopy measurements are performed on two groups of blood serum samples,which are from 28 echinococcosis patients and 38 healthy persons,respectively. The normalized Raman reflection spectra show that the reflectivity of the echinococcosis blood serum is higher than that of the normal human blood serum in the wavelength ranges of 101—175 nm and 1 801—2 701 nm. Then the principal component analysis(PCA) and back propagation neural network(BPNN) model are used to obtain the diagnosis results. The diagnosis rates for healthy persons and echinococcosis persons are 93.333 3% and 90.909 1%,respectively,so the average final diagnosis rate is 92.121 2%. The results demonstrate that the Raman spectroscopy analysis of blood serum combined with PCA-BPNN has considerable potential for the non-invasive and rapid detection of echinococcosis.
