A method for predicting information propagation in a social network includes acquiring target information to be predicted, and acquiring influences of K clusters, where the target information is posted or forwarded by a first user at a first moment, and K is a positive integer; determining a role probability distribution of the first user, and determining a second user who has not propagated the target information, where the role probability distribution of the first user is used to indicate probabilities that the first user belongs separately to the K clusters; and determining, according to the influences of the K clusters and the role probability distribution of the first user, a probability that the second user forwards the target information from the first user. In the embodiments of the present application, propagation of target information in a social network can be predicted by using influences of K clusters.
Please help me write a proper abstract based on the patent claims. CLAIM: 1. A method for predicting information propagation in a social network, wherein each user of the social network is registered at the social network with a set of characteristic attributes, users of the social network are grouped into K clusters each represented by a different characteristic vector, and K is a positive integer, wherein the method is performed by a computing device, and the method comprises: acquiring information of an object that is posted or forwarded by a first user of the social network; determining influences of the K clusters, wherein the influences of the K clusters correspond to propagation success rates of the object in the K clusters; determining a role probability distribution of the first user according to the set of characteristic attributes of the first user and the characteristic vectors of the K clusters, wherein the role probability distribution of the first user indicates probabilities that the first user belongs to each of the K clusters; identifying a second user who has not propagated the object; and determining, according to the influences of the K clusters and the role probability distribution of the first user, a probability that the second user forwards the object from the first user. 2. The method according to claim 1, wherein the object is posted or forwarded by the first user at an initial moment, and wherein the method further comprises: outputting an account of the second user who meets a preset condition, wherein the preset condition is that the probability of forwarding the object by the second user is greater than a preset probability threshold. 3. The method according to claim 1, further comprising: acquiring an information propagation record, a user relationship database, and a user characteristics database of the social network, wherein the information propagation record comprises a historical propagation record of existing information, the user relationship database comprises a follow relationship between existing users, and the user characteristics database comprises characteristic attributes of the existing users; and obtaining the K clusters and characteristic vectors of the K clusters according to the user characteristics database by using a soft clustering algorithm, wherein the K clusters and characteristic vectors of the K clusters are determined according to the characteristic attributes of the existing users; wherein the influences of the K clusters are obtained according to the information propagation record and the user relationship database by using a learning method. 4. The method according to claim 1, wherein the characteristic attributes of the first user form a characteristic vector AT, and the characteristic vectors of the K clusters are indicated by KTj, respectively, wherein j=1, 2, . . . , K; and wherein the role probability distribution of the first user is determined by:  AT - KT j  ∑ j = 1 K   AT - KT j  × 100  % respectively. 5. The method according to claim 3, further comprising: determining role probability distributions of the existing users according to the user characteristics database and the characteristic vectors of the K clusters, wherein the role probability distributions of the existing users indicates probabilities that the existing users belong to each of the K clusters. 6. The method according to claim 3, wherein the first user belongs to the existing users of the social network, and wherein determining the role probability distribution of the first user according to the set of characteristic attributes of the first user and the characteristic vectors of the K clusters comprises: determining role probability distributions of the existing users according to the user characteristics database and the characteristic vectors of the K clusters, wherein the role probability distributions of the existing users indicates probabilities that the existing users belong to each of the K clusters; and acquiring the role probability distribution of the first user from the role probability distributions of the existing users. 7. The method according to claim 3, wherein the first user does not belong to the existing users of the social network, and wherein determining the role probability distribution of the first user according to the set of characteristic attributes of the first user and the characteristic vectors of the K clusters comprises: acquiring characteristic attributes of the first user; acquiring characteristic attributes of N third users from the user characteristics database according to the characteristic attributes of the first user, wherein the N third users belong to the existing users, distances between the characteristic attributes of the N third users and the characteristic attributes of the first user are less than a preset distance threshold, and N is a positive integer; acquiring role probability distributions of the N third users from the role probability distributions of the existing users; and determining the role probability distribution of the first user according to the role probability distributions of the N third users. 8. The method according to claim 7, wherein the determining the role probability distribution of the first user according to the role probability distributions of the N third users comprises: determining that the role probability distribution of the first user is an arithmetic mean of the role probability distributions of the N third users. 9. The method according to claim 3, wherein the learning method is a machine learning method or a statistical learning method. 10. The method according to claim 1, wherein determining, according to the influences of the K clusters and the role probability distribution of the first user, a probability that the second user forwards the object from the first user comprises: calculating, according to the influences of the K clusters and the role probability distribution of the first user by using a statistical method, an expected value of a propagation probability that the second user forwards the object; wherein the expected value of the propagation probability is used as the probability that the second user forwards the object from the first user. 11. The method according to claim 1, wherein the influences of the K clusters further comprise information propagation time delay rates of the K clusters, and the method further comprises: predicting, according to the influences of the K clusters and the role probability distribution of the first user, a moment at which the second user forwards the target information from the first user. 12. The method according to claim 1, wherein the second user is a user who is among followers of the first user. 13. The method according to claim 12, wherein identifying a second user who has not propagated the object comprises: determining the followers of the first user according to the user relationship database; and determining the second user among the followers of the first user who have not propagated the target information. 14. A system for predicting information propagation in a social network, wherein each user of the social network is registered at the social network with a set of characteristic attributes, users of the social network are grouped into K clusters each represented by a different characteristic vector, and K is a positive integer, wherein the system comprises: a memory, configured to store information of the users of the social network; and a processor, configured to: acquire information of an object that is posted or forwarded by a first user of the social network; determine influences of the K clusters, wherein the influences of the K clusters correspond to propagation success rates of the object in the K clusters; determine a role probability distribution of the first user according to the set of characteristic attributes of the first user and the characteristic vectors of the K clusters, wherein the role probability distribution of the first user indicates probabilities that the first user belongs to each of the K clusters; identify a second user who has not propagated the object; and determine, according to the influences of the K clusters and the role probability distribution of the first user, a probability that the second user forwards the object from the first user. 15. The system according to claim 14, further comprising: an output device, configured to output an account of the second user who meets a preset condition, wherein the preset condition is that the probability of forwarding the object by the second user is greater than a preset probability threshold. 16. The system according to claim 14, wherein the processor is further configured to: acquire an information propagation record, a user relationship database, and a user characteristics database of the social network, wherein the information propagation record comprises a historical propagation record of existing information, the user relationship database comprises a follow relationship between existing users, and the user characteristics database comprises characteristic attributes of the existing users; and obtain the K clusters and characteristic vectors of the K clusters according to the user characteristics database by using a soft clustering algorithm, wherein the K clusters and characteristic vectors of the K clusters are determined according to the characteristic attributes of the existing users; wherein the influences of the K clusters are obtained according to the information propagation record and the user relationship database by using a learning method. 17. The system according to claim 14, wherein the characteristic attribute of the first user form a characteristic vector AT, and the characteristic vectors of the K clusters are indicated by KTj, respectively, wherein j=1, 2, . . . , K, and wherein the role probability distribution of the first user is determined by  AT - KT j  ∑ j = 1 K   AT - KT j  × 100  % respectively. 18. The system according to claim 16, wherein the processor is further configured to: determine role probability distributions of the existing users according to the user characteristics database and the characteristic attributes of the K clusters, wherein the role probability distributions of the existing users are used to indicate probabilities that the existing users belong separately to the K clusters. 19. A computer program product comprising a non-transitory computer-readable storage medium storing program codes thereon for use by a computing device to predict information propagation in a social network, wherein each user of the social network is registered at the social network with a set of characteristic attributes, users of the social network are grouped into K clusters each represented by a different characteristic vector, and K is a positive integer, and wherein the program codes comprise instructions for: acquiring information of an object that is posted or forwarded by a first user of the social network; determining influences of the K clusters, wherein the influences of the K clusters correspond to propagation success rates of the object in the K clusters; determining a role probability distribution of the first user according to the set of characteristic attributes of the first user and the characteristic vectors of the K clusters, wherein the role probability distribution of the first user indicates probabilities that the first user belongs to each of the K clusters; identifying a second user who has not propagated the object; and determining, according to the influences of the K clusters and the role probability distribution of the first user, a probability that the second user forwards the object from the first user. 20. The computer program product according to claim 19, wherein the program codes further comprise instructions for: acquiring an information propagation record, a user relationship database, and a user characteristics database of the social network, wherein the information propagation record comprises a historical propagation record of existing information, the user relationship database comprises a follow relationship between existing users, and the user characteristics database comprises characteristic attributes of the existing users; and obtaining the K clusters and characteristic vectors of the K clusters according to the user characteristics database by using a soft clustering algorithm, wherein the K clusters and characteristic vectors of the K clusters are determined according to the characteristic attributes of the existing users; wherein the influences of the K clusters are obtained according to the information propagation record and the user relationship database by using a learning method.