An information processing device includes a morphological-analysis performing unit that performs morphological analysis on character strings to identify the word classes of words included in the character strings; a specifying unit that specifies a permutation of target terms, which are words selected from the character strings, on the basis of the identified word classes; and a generating unit that calculates permutation pointwise mutual information, which is pointwise mutual information of the permutation in a corpus, and learns the permutation and the permutation pointwise mutual information, to generate a permutation pointwise-mutual-information model, which is a trained model.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The disclosure relates to a learning device, an inference device, a non-transitory computer-readable medium, a learning method, and an inference method.

2. Description of the Related Art

Conventionally, there is a method that uses deep learning to calculate the likelihood of inference for common sense inference processing of a natural language (for example, refer to Patent Literature 1).Patent Literature 1: U.S. Pat. No. 10,452,978

SUMMARY OF TRE INVENTION

However, in the conventional technique, the computational effort is enormous because the meaning of words is converted to context-dependent distributed representations, which are then subjected to dimensional compression.

Accordingly, an object of one or more aspects of the disclosure is to allow model learning and inference to be performed with a small computational effort.

A learning device according to a first aspect of the disclosure includes: processing circuitry to perform morphological analysis on a plurality of character strings to identify word classes of a plurality of words included in the character strings; to specify a permutation of a plurality of target terms on a basis of the identified word class, the target terms being words selected from the character strings; and to calculate pointwise mutual information of the permutation in a corpus and learn the permutation and the pointwise mutual information of the permutation to generate a permutation pointwise mutual-information model, the pointwise mutual information of the permutation being permutation pointwise mutual information, the permutation pointwise-mutual-information model being a trained model.

A learning device according to second aspect of the disclosure includes: processing circuitry to perform morphological analysis on first character strings to identify word classes of a plurality of words included in the first character strings, and to perform morphological analysis on a plurality of second character strings constituting an answer text to the question text to identify word classes of a plurality of words included in the second character strings, the first character strings including a character string constituting a question text and a plurality of character strings constituting an answer text to the question text; to specify a combination of first target terms on a basis of the word classes identified for the first character strings, and to specify a permutation of second target terms on a basis of the word classes identified for the second character strings, the first target terms being words selected from the first character strings, the second target terms being words selected from second character strings; and to generate a combination pointwise-mutual-information model by calculating pointwise mutual information of the combination in a corpus and learning the combination and the pointwise mutual information of the combination, and to generate a permutation pointwise-mutual-information model by calculating pointwise mutual information of the permutation in a corpus and learning the permutation and the pointwise mutual information of the permutation, the pointwise mutual information of the combination being combination pointwise mutual information, the combination pointwise-mutual-information model being a trained model, the pointwise mutual information of the permutation being permutation pointwise mutual information, the permutation pointwise-mutual-information model being a trained model.

An inference device according to a first aspect of the disclosure is configured to make an inference by referring to a permutation pointwise-mutual-information model, the permutation pointwise-mutual-information model being a trained model trained by a permutation of a plurality of words of a predetermined word class and permutation pointwise mutual information, the permutation pointwise mutual information being pointwise mutual information of the permutation in a corpus, the inference device including: processing circuitry to acquire a step count of two or more for an answer to a question text; to extract a same number of candidate texts as the step count from the candidate texts to be candidates of the answer to the question text and concatenate the two or more extracted candidate texts, to generate a plurality of procedural texts each including the two or more candidate texts; to perform morphological analysis on each of the procedural texts to identify word classes of a plurality of words included in each of the procedural texts; and to specify a permutation of a plurality of target terms on a basis of the identified word classes and specify a likelihood of the specified permutation by referring to the permutation pointwise-mutual-information model, to specify a ranking likelihood, the target terms being words selected from each of the procedural texts, the ranking likelihood being a likelihood of each of the procedural texts.

An inference device according to a second aspect of the disclosure is configured to make an inference by referring to a combination pointwise-mutual-information model and a permutation pointwise-mutual-information model, the combination pointwise-mutual-information model being a trained model trained by a combination of words of a predetermined word class and combination pointwise mutual information, the combination pointwise mutual information being pointwise mutual information of the combination in a corpus, the permutation pointwise-mutual-information model being a trained model trained by a permutation of words of a predetermined word class and permutation pointwise mutual information, the permutation pointwise mutual information being pointwise mutual information of the permutation in a corpus, the inference device including: processing circuitry to acquire a question text and a step count of two or more for an answer to the question text; to extract a same number of candidate texts as the step count from the candidate texts to be candidates of the answer to the question text and concatenate the two or more extracted candidate texts, to generate a plurality of procedural texts each including the two or more candidate texts and to generate a plurality of question-answering procedural texts by concatenating the question text in front of each of the procedural texts; to perform morphological analysis on each of the question-answering procedural texts to identify word classes of a plurality of words included in each of the question-answering procedural texts; to specify a combination of a plurality of first target terms selected from each of the question-answering procedural texts on a basis of the identified word classes, refer to the combination pointwise-mutual-information model, and specify a likelihood of the specified combination, to specify a first likelihood of each of the procedural texts; to generate a plurality of target procedural texts by deleting the question text from a plurality of question-answering procedural texts extracted by narrowing down the procedural texts with the first likelihood; and to specify a permutation of a plurality of second target terms selected from each of the target procedural texts on a basis of the identified word classes, refer to the permutation pointwise-mutual-information model, and specify a likelihood of the specified permutation, to specify a ranking likelihood, the ranking likelihood being a likelihood of each of the procedural texts.

An inference device according to a third aspect of the disclosure is configured to make an inference by referring to a combination pointwise-mutual-information model, a permutation pointwise-mutual-information model, and a target trained model, the combination pointwise-mutual-information model being a trained model trained by a combination of words of a predetermined word class and combination pointwise mutual information, the combination pointwise mutual information being pointwise mutual information of the combination in a corpus, the permutation pointwise-mutual-information model being a trained model trained by a permutation of words of a predetermined word class and permutation pointwise mutual information, the permutation pointwise mutual information being pointwise mutual information of the permutation in a corpus, the target trained model being a trained model different from the combination pointwise-mutual-information model and the permutation pointwise-mutual-information model, the inference device including: processing circuitry to acquire a question text and a step count of two or more for an answer to the question text; to extract a same number of candidate texts as the step count from the candidate texts to be candidates of the answer to the question text and concatenate the two or more extracted candidate texts, to generate a plurality of procedural texts each including the two or more candidate texts and to generate a plurality of question-answering procedural texts by concatenating the question text in front of each of the procedural texts; to perform morphological analysis on each of the question-answering procedural texts to identify word classes of a plurality of words included in each of the question-answering procedural texts; to specify a combination of a plurality of first target terms selected from each of the question-answering procedural texts on a basis of the identified word classes, refer to the combination pointwise-mutual-information model, and specify a likelihood of the specified combination, to specify a first likelihood of each of the procedural texts; to generate a plurality of first target procedural texts by deleting the question text from a plurality of question-answering procedural texts extracted by narrowing down the procedural texts with the first likelihoods; to specify a permutation of a plurality of second target terms selected from each of the first target procedural texts on a basis of the identified word classes, refer to the permutation pointwise-mutual-information model, and specify a likelihood of the specified permutation, to specify a second likelihood of each of the first target procedural texts; to narrow down the first target procedural texts with the second likelihoods to extract a plurality of second target procedural texts; and to refer to the target trained model to specify a ranking likelihood, the ranking likelihood being a likelihood of each of the second target procedural texts.

A non-transitory computer-readable medium that stores therein a program according to a first aspect of the disclosure causes a computer to execute processes of: performing morphological analysis on a plurality of character strings to identify word classes of a plurality of words included in the character strings; specifying a permutation of a plurality of target terms on a basis of the identified word classes, the target terms being words selected from the character strings; and calculating pointwise mutual information of the permutation in a corpus and learning the permutation and the pointwise mutual information of the permutation to generate a permutation pointwise-mutual-information model, the pointwise mutual information of the permutation being permutation pointwise mutual information, the permutation pointwise-mutual-information model being a trained model.

A non-transitory computer-readable medium that stores therein a program according to a second aspect of the disclosure causes a computer to execute processes of: performing morphological analysis on first character strings to identify word classes of a plurality of words included in the first character strings, and performing morphological analysis on a plurality of second character strings constituting an answer text to the question text to identify word classes of a plurality of words included in the second character strings, the first character strings including a character string constituting a question text and a plurality of character strings constituting an answer text to the question text; specifying a combination of first target terms on a basis of the word classes identified for the first character strings, and specifying a permutation of second target terms on a basis of the word classes identified for the second character strings, the first target terms being words selected from the first character strings, the second target terms being words selected from second character strings; and generating a combination pointwise-mutual-information model by calculating pointwise mutual information of the combination in a corpus and by learning the combination and the pointwise mutual information of the combination, and generating a permutation pointwise-mutual-information model by calculating pointwise mutual information of the permutation in a corpus and by learning the permutation and the pointwise mutual information of the permutation, the pointwise mutual information of the combination being combination pointwise mutual information, the combination pointwise-mutual-information model being a trained model, the pointwise mutual information of the permutation being permutation pointwise mutual information, the permutation pointwise-mutual-information model being a trained model.

A non-transitory computer-readable medium that stores therein a program according to a third aspect of the disclosure causes a computer to execute a process of making an inference by referring to a permutation pointwise-mutual-information model, the permutation pointwise-mutual-information model being a trained model trained by a permutation of a plurality of words of a predetermined word class and permutation pointwise mutual information, the permutation pointwise mutual information being pointwise mutual information of the permutation in a corpus, the program further causing the computer to execute processes of: acquiring a step count of two or more for an answer to a question text; extracting a same number of candidate texts as the step count from the candidate texts to be candidates of the answer to the question text and concatenating the two or more extracted candidate texts, to generate a plurality of procedural texts each including the two or more candidate texts; performing morphological analysis on each of the procedural texts to identify word classes of a plurality of words included in each of the procedural texts; and specifying a permutation of a plurality of target terms on a basis of the identified word classes and specifying a likelihood of the specified permutation by referring to the permutation pointwise-mutual-information model, to specify a ranking likelihood, the target terms being words selected from each of the procedural texts, the ranking likelihood being a likelihood of each of the procedural texts.

A non-transitory computer-readable medium that stores therein a program according to a fourth aspect of the disclosure causes a computer to execute a process of making an inference by referring to a combination pointwise-mutual-information model and a permutation pointwise-mutual-information model, the combination pointwise-mutual-information model being a trained model trained by a combination of words of a predetermined word class and combination pointwise mutual information, the combination pointwise mutual information being pointwise mutual information of the combination in a corpus, the permutation pointwise-mutual-information model being a trained model trained by a permutation of words of a predetermined word class and permutation pointwise mutual information, the permutation pointwise mutual information being pointwise mutual information of the permutation in a corpus, the program further causing the computer to execute processes of: acquiring a question text and a step count of two or more for an answer to the question text; extracting a same number of candidate texts as the step count from the candidate texts to be candidates of an answer to the question text and concatenating the two or more extracted candidate texts, to generate a plurality of procedural texts each including the two or more candidate texts and to generate a plurality of question-answering procedural texts by concatenating the question text in front of each of the procedural texts; performing morphological analysis on each of the question-answering procedural texts to identify word classes of a plurality of words included in each of the question-answering procedural texts; and specifying a combination of a plurality of first target terms selected from each of the question-answering procedural texts on a basis of the identified word classes, referring to the combination pointwise-mutual-information model, and specifying a likelihood of the specified combination, to specify a first likelihood of each of the procedural texts; generating a plurality of target procedural texts by deleting the question text from a plurality of question-answering procedural texts extracted by narrowing down the procedural texts with the first likelihood; and specifying a permutation of a plurality of second target terms selected from each of the target procedural texts on a basis of the identified word classes, referring to the permutation pointwise-mutual-information model, and specifying a likelihood of the specified permutation, to specify a ranking likelihood, the ranking likelihood being a likelihood of each of the procedural texts.

A non-transitory computer-readable medium that stores therein a program according to a fifth aspect of the disclosure causes a computer to execute a process of making an inference by referring to a combination pointwise-mutual-information model, a permutation pointwise-mutual-information model, and a target trained model, the combination pointwise-mutual-information model being a trained model trained by a combination of words of a predetermined word class and combination pointwise mutual information, the combination pointwise mutual information being pointwise mutual information of the combination in a corpus, the permutation pointwise-mutual-information model being a trained model trained by a permutation of words of a predetermined word class and permutation pointwise mutual information, the permutation pointwise mutual information being pointwise mutual information of the permutation in a corpus, the target trained model being a trained model different from the combination pointwise-mutual-information model and the permutation pointwise-mutual-information model, the program further causing the computer to execute processes of: acquiring a question text and a step count of two or more for an answer to the question text; extracting a same number of candidate texts as the step count from the candidate texts to be candidates of an answer to the question text and concatenating the two or more extracted candidate texts, to generate a plurality of procedural texts each including the two or more candidate texts and to generate a plurality of question-answering procedural texts by concatenating the question text in front of each of the procedural texts; performing morphological analysis on each of the question-answering procedural texts to identify word classes of a plurality of words included in each of the question-answering procedural texts; specifying a combination of a plurality of first target terms selected from each of the question-answering procedural texts on a basis of the identified word classes, referring to the combination pointwise-mutual-information model, and specifying a likelihood of the specified combination, to specify a first likelihood of each of the procedural texts; generating a plurality of first target procedural texts by deleting the question text from a plurality of question-answering procedural texts extracted by narrowing down the procedural texts with the first likelihoods; specifying a permutation of a plurality of second target terms selected from each of the first target procedural texts on a basis of the identified word classes, referring to the permutation pointwise-mutual-information model, and specifying a likelihood of the specified permutation, to specify a second likelihood of each of the first target procedural texts; and narrowing down the first target procedural texts with the second likelihoods to extract a plurality of second target procedural texts; and referring to the target trained model to specify a ranking likelihood, the ranking likelihood being a likelihood of each of the second target procedural texts.

A learning method according to a first aspect of the disclosure includes: performing morphological analysis on a plurality of character strings to identify word classes of a plurality of words included in the character strings; specifying a permutation of a plurality of target terms on a basis of the identified word classes, the target terms being a plurality of words selected from the character strings; calculating permutation pointwise mutual information, the permutation pointwise mutual information being pointwise mutual information of the permutation in a corpus; and generating a permutation pointwise-mutual-information model by learning the permutation and the permutation pointwise mutual information, the permutation pointwise-mutual-information model being a trained model.

A learning method according to a second aspect of the disclosure includes: performing morphological analysis on a plurality of first character strings to identify word classes of a plurality of words included in the first character strings, the first character strings including a character string constituting a question text and a plurality of character strings constituting an answer text to the question text; performing morphological analysis on a plurality of second character strings to identify word classes of a plurality of words included in the second character strings, the second character strings being a plurality of character strings constituting an answer text to the question text; specifying a combination of a plurality of first target terms on a basis of the word classes identified in the first character strings, the first target terms being a plurality of words selected from the first character strings; specifying a permutation of a plurality of second target terms on a basis of the word classes identified in the second character strings, the second target terms being a plurality of words selected from the second character strings; calculating combination pointwise mutual information, the combination pointwise mutual information being pointwise mutual information of the combination in a corpus; generating a combination pointwise-mutual-information model by learning the combination and the combination pointwise mutual information, the combination pointwise-mutual-information model being a trained model; calculating permutation pointwise mutual information, the permutation pointwise mutual information being pointwise mutual information of the permutation in a corpus; and generating a permutation pointwise-mutual-information model by learning the permutation and the permutation pointwise mutual information, the permutation pointwise-mutual-information model being a trained model.

An inference method according to a first aspect of the disclosure is a method of making an inference by referring to a permutation pointwise-mutual-information model, the permutation pointwise-mutual-information model being a trained model trained by a permutation of a plurality of words of a predetermined word class and permutation pointwise mutual information, the permutation pointwise mutual information being pointwise mutual information of the permutation in a corpus, the method including: acquiring a step count of two or more for an answer to a question text; extracting a same number of candidate texts as the step count from the candidate texts to be candidates of the answer to the question text and concatenating the two or more extracted candidate texts, to generate a plurality of procedural texts each including the two or more candidate texts; performing morphological analysis on each of the procedural texts to identify word classes of a plurality of words included in each of the procedural texts; and specifying a permutation of a plurality of target terms on a basis of the identified word classes and specify a likelihood of the specified permutation by referring to the permutation pointwise-mutual-information model, to specify a ranking likelihood, the target terms being words selected from each of the procedural texts, the ranking likelihood being a likelihood of each of the procedural texts.

An inference method according to a second aspect of the disclosure is a method of making an inference by referring to a combination pointwise-mutual-information model and a permutation pointwise-mutual-information model, the combination pointwise-mutual-information model being a trained model trained by a combination of words of a predetermined word class and combination pointwise mutual information, the combination pointwise mutual information being pointwise mutual information of the combination in a corpus, the permutation pointwise-mutual-information model being a trained model trained by a permutation of words of a predetermined word class and permutation pointwise mutual information, the permutation pointwise mutual information being pointwise mutual information of the permutation in a corpus, the method including: acquiring a question text and a step count of two or more for an answer to the question text; extracting a same number of candidate texts as the step count from the candidate texts to be candidates of the answer to the question text and concatenating the two or more extracted candidate texts, to generate a plurality of procedural texts each including the two or more candidate texts; generating a plurality of question-answering procedural texts by concatenating the question text in front of each of the procedural texts; performing morphological analysis on each of the question-answering procedural texts to identify word classes of a plurality of words included in each of the question-answering procedural texts; specifying a combination of a plurality of first target terms selected from each of the question-answering procedural texts on a basis of the identified word classes, referring to the combination pointwise-mutual-information model, and specifying a likelihood of the specified combination, to specify a first likelihood, the first likelihood being a likelihood of each of the procedural texts; generating a plurality of target procedural texts by narrowing down the procedural texts with the first likelihoods to delete the question text from the extracted question-answering procedural texts; and specifying a permutation of a plurality of second target terms selected from each of the target procedural texts on a basis of the identified word classes, refer to the permutation pointwise-mutual-information model, and specify a likelihood of the specified permutation, to specify a ranking likelihood, the ranking likelihood being a likelihood of each of the procedural texts.

An inference method according to a third aspect of the disclosure is a method of making an inference by referring to a combination pointwise-mutual-information model, a permutation pointwise-mutual-information model, and a target trained model, the combination pointwise-mutual-information model being a trained model trained by a combination of words of a predetermined word class and combination pointwise mutual information, the combination pointwise mutual information being pointwise mutual information of the combination in a corpus, the permutation pointwise-mutual-information model being a trained model trained by a permutation of words of a predetermined word class and permutation pointwise mutual information, the permutation pointwise mutual information being pointwise mutual information of the permutation in a corpus, the target trained model being a trained model different from the combination pointwise-mutual-information model and the permutation pointwise-mutual-information model, the method including: acquiring a question text and a step count of two or more for an answer to the question text; extracting a same number of candidate texts as the step count from the candidate texts to be candidates of the answer to the question text and concatenating the two or more extracted candidate texts, to generate a plurality of procedural texts each including the two or more candidate texts; generating a plurality of question-answering procedural texts by concatenating the question text in front of each of the procedural texts; performing morphological analysis on each of the question-answering procedural texts to identify word classes of a plurality of words included in each of the question-answering procedural texts; specifying a combination of a plurality of first target terms selected from each of the question-answering procedural texts on a basis of the identified word classes, referring to the combination pointwise-mutual-information model, and specifying a likelihood of the specified combination, to specify a first likelihood, the first likelihood being a likelihood of each of the procedural texts; generate a plurality of first target procedural texts by deleting the question text from a plurality of question-answering procedural texts extracted by narrowing down the procedural texts with the first likelihoods; specifying a permutation of a plurality of second target terms selected from each of the first target procedural texts on a basis of the identified word classes, referring to the permutation pointwise-mutual-information model, and specifying a likelihood of the specified permutation, to specify a second likelihood, the second likelihood being a likelihood of each of the first target procedural texts; extracting a plurality of second target procedural texts by narrowing down the first target procedural texts with the second likelihoods; and referring to the target trained model to specify a ranking likelihood, the ranking likelihood being a likelihood of each of the second target procedural texts.

According to one or more aspects of the disclosure, model learning and inference can be performed with a small computational effort.

DETAILED DESCRIPTION OF THE INVENTION

First Embodiment

FIG.1is a block diagram schematically illustrating a configuration of an information processing device100functioning as a learning device according to the first embodiment.

The information processing device100includes an acquiring unit101, a morphological-analysis performing unit102, a specifying unit103, a communication unit104, a generating unit105, and a model storage unit106.

The acquiring unit101acquires training data. The training data is text data including character strings. For example, the acquiring unit101may acquire the training data from another device via the communication unit104or may acquire the training data from a user or the like via an input unit (not illustrated). The acquiring unit101then gives the training data to the morphological-analysis performing unit102. Here, the character strings are answers to a question text.

The morphological-analysis performing unit102performs morphological analysis on the character strings represented by the training data to identify the word classes of the words in the character strings.

The morphological-analysis performing unit102then gives, to the specifying unit103, word class data representing the words of identified word classes.

The specifying unit103specifies, on the basis of the identified word classes, the permutations of target terms or words selected from the words of identified word classes represented by the word class data. Here, the target terms are assumed to be one argument and two predicates but are not limited to such examples. The specifying unit103then gives permutation data representing the specified permutations to the generating unit105.

Here, a predicate is a verb, an adjective, an adjective verb, or a noun that can form a verb by adding “suru,” and a predicate is a word that can be a subject or an object, which here is a noun.

The communication unit104communicates with other devices. Here, the communication unit104communicates with, for example, a server (not illustrated) on the Internet, to connect to a corpus stored on the server. A corpus is a structured, large-scale data collection of natural language texts.

The generating unit105connects to a corpus via the communication unit104and calculates the permutation pointwise mutual information, which is the permutation pointwise mutual information of the permutations of the one argument and two predicates represented by the permutation data in the corpus.

The permutation pointwise mutual information is calculated, for example, by the following equation (1):

Here, w1kdenotes an argument that appears first in a permutation of one argument and two predicates represented by the permutation data; v2idenotes a predicate that appears second in the permutation represented by the permutation data; v3jdenotes a predicate that appears third in the permutation represented by the permutation data.

P(wk) denotes the probability of appearance of the argument wkand is the number of appearances of the argument wkrelative to the total number of words in the corpus. P(vi) denotes the probability of appearance of the predicate viand is the number of appearances of the argument virelative to the total number of words in the corpus. P(vj) denotes the probability of appearance of the predicate vjand is the number of appearances of the argument vjrelative to the total number of words in the corpus. P(w1x, v2i, v3j) denotes the probability of appearance of the argument wx, the predicate vi, and the predicate vjin this order in the corpus, and is the number of texts in which the argument w1k, the predicate v2i, and the predicate v3jappear in this order relative to the total number of words in the corpus.

Here, when the argument wkappears second, the permutation pointwise mutual information is calculated, for example, by the following equation (2):

When the argument wkappears third, the permutation pointwise mutual information is calculated, for example, by the following equation (3):

For example, “pen wo motte kaku (Hold a pen and write)” and “pen de kaite motsu (Write with a pen and hold)” have different meanings, so by calculating the probability of appearance in permutations of one argument and two predicates, it is possible to train a model in accordance with the difference in meaning caused by the order of the three words: pen, hold, and write. Since function words have no substantial meaning, they are deleted when the morphological analysis described later is performed; “pen wo motte kaku (Hold a pen and write)” is converted to the standard form of content words, “pen, motsu, kaku (hold, pen, write),” and similarly “pen de kaite motsu (Write with a pen and hold)” is converted to “pen, kaku, motsu (write, pen, hold)”; in other words, different patterns of permutations can be learned with different likelihoods even through a bag-of-words model composed of the same words.

The generating unit105then learns the permutations of one argument and two predicates and the calculated permutation pointwise mutual information, to generate a permutation pointwise-mutual-information model, which is a trained model. The generated permutation pointwise-mutual-information model is stored in the model storage unit106. The permutation pointwise-mutual-information model is, for example, a model in which the permutation pointwise mutual information of one argument and two predicates is a second-order tensor. In the following, the second-order tensor is referred to as a triaxial tensor.

The model storage unit106is a storage unit that stores the permutation pointwise-mutual-information model.

FIG.2is a block diagram schematically illustrating a configuration of a computer120as an implementation example of the information processing device100.

The information processing device100can be implemented by the computer120that includes a non-volatile memory121, a volatile memory122, a network interface card (NIC)123, and a processor124.

The non-volatile memory121is an auxiliary storage that stores data and programs necessary for processing by the information processing device100. For example, the non-volatile memory121is a hard disk drive (HDD) or a solid state drive (SSD).

The volatile memory122is a main storage that provides a work area to the processor124. For example, the volatile memory122is a random access memory (RAM).

The NIC123is a communication interface for communicating with other devices.

The processor124controls the processing by the information processing device100. For example, the processor124is a central processing unit (CPU) or a field-programmable gate array (FPGA). The processor124may be a multiprocessor.

For example, the acquiring unit101, the morphological-analysis performing unit102, the specifying unit103, and the generating unit105can be implemented by the processor124loading the programs stored in the non-volatile memory121to the volatile memory122and executing these programs. Such programs may be provided via a network or may be recorded and provided on a recording medium. That is, such programs may be provided as, for example, program products.

The model storage unit106can be implemented by the non-volatile memory121.

The communication unit104can be implemented by the WIC123.

The information processing device100may be implemented by a processing circuit or may be implemented by software, firmware, or a combination of these. The processing circuit may be a single circuit or a composite circuit.

In other words, the information processing device100can be implemented by processing circuitry.

FIG.3is a flowchart illustrating an operation of learning a permutation pointwise-mutual-information model by the information processing device100according to the first embodiment.

First, the acquiring unit101acquires training data (step S10). The acquiring unit101then gives the training data to the morphological-analysis performing unit102.

The morphological-analysis performing unit102performs morphological analysis on the character strings represented by the training data, to identify the word classes of the words in the character strings (step S11). In the present embodiment, the morphological-analysis performing unit102then deletes words of word classes other than verbs, adjectives, adjective verbs, nouns that can form verbs by adding “suru,” and nouns from the words of identified word classes and converts the remaining words into standard forms. The morphological-analysis performing unit102then gives word class data representing the words converted into standard forms and the words that do not need to be converted into standard forms, to the specifying unit103.

The specifying unit103determines whether or not the words of identified word classes and represented by the word class data include two or more predicates (step S12). If two or more predicates are included (Yes in step S12), the process proceeds to step S13, and if one or fewer predicates are included (No in step S12), the process ends. In the present embodiment, a word is determined to be a predicate when the word class of the word is any one of a verb, an adjective, an adjective verb, and a noun that can form a verb by adding “suru.”

In step S13, the specifying unit103specifies a permutation consisting of one argument and two predicates in the words of identified word classes and represented by the word class data. The permutation specified here is a permutation for which the permutation pointwise mutual information has not yet been calculated in step S14. The specifying unit103then gives permutation data representing the specified permutation to the generating unit105. Here, the words that are not determined to be predicates are determined to be arguments.

The generating unit105connects to a corpus via the communication unit104to calculate permutation pointwise mutual information, which is pointwise mutual information of the corpus, of the permutation of one argument and two predicates represented by the permutation data (step S14). The generating unit105then learns one argument, two predicates, and the calculated permutation pointwise mutual information, associates these with each other, and registers these in the permutation pointwise-mutual-information model stored in the model storage unit106.

Next, the specifying unit103determines whether or not there is a permutation for which the permutation pointwise mutual information has not yet been calculated (step S15). If such a permutation remains (Yes in step S15), the process returns to step S13, and if no such permutation remains (No in step S15), the process ends.

As described above, according to the first embodiment, pointwise mutual information corresponding to the order of appearance of the one argument and two predicates can be accumulated as a trained model.

In the first embodiment, the generating unit105is connected to an external corpus via the communication unit104, but the first embodiment is not limited to such an example. For example, a corpus may be stored in the model storage unit106or another storage unit not illustrated. In such a case, the communication unit104is not needed.

In the first embodiment, the model storage unit106is provided in the information processing device100, but the first embodiment is not limited to such an example. For example, the generating unit105may store the permutation pointwise-mutual-information model in a storage unit provided in another device (not illustrated) via the communication unit104. In such a case, the model storage unit106in the information processing device100is not needed.

Second Embodiment

FIG.4is a block diagram schematically illustrating a configuration of an information processing device200functioning as an inference device according to the second embodiment.

The information processing device200includes an acquiring unit201, a communication unit202, a procedural-text generating unit203, a morphological-analysis performing unit204, an inference unit205, and a ranking unit206.

The inference device according to the second embodiment is a device that makes an inference by referring to a permutation pointwise-mutual-information model.

The acquiring unit201acquires step count data. The step count data is data representing the number of steps of answering a question text. For example, the acquiring unit201may acquire the step count data from another device via the communication unit202or may acquire the step count data via an input unit (not illustrated). Here, the step count is two or more. Thus, the acquiring unit201acquires a step count of two or more.

The acquiring unit201then gives the step count data to the procedural-text generating unit203.

The communication unit202communicates with other devices. Here, the communication unit202communicate with, for example, a server on the Internet to enable reception of data from a candidate-text storage unit130or a model storage unit131provided in the server.

Here, the candidate-text storage unit130stores candidate text data representing candidate texts to be candidates of an answer to the question text.

The model storage unit131stores a permutation pointwise-mutual-information model generated through an operation that is the same as that in the first embodiment as a trained model.

The procedural-text generating unit203refers to the candidate text data stored in the candidate-text storage unit130via the communication unit202to extract the same number of candidate texts as the step count represented by the step count data from the acquiring unit201, and concatenates two or more extracted candidate texts to generate procedural texts. For example, if the step count is “2,” one candidate text is “Measure rice into an inner pot,” and the next candidate text is “Rince rice,” one of the permutations of these candidate texts is the procedural text “Measure rice into inner pot. Rince rice.” In this case, another one of the permutations “Rince rice. Measure rice into inner pot” is also a procedural text. In other words, each of the procedural texts consists of two or more extracted candidate texts. The procedural-text generating unit203gives procedural text data representing procedural texts to the morphological-analysis performing unit204.

The morphological-analysis performing unit204performs morphological analysis on each of the procedural texts represented by the procedural text data to identify the word class of each word in each of the procedural texts. The morphological-analysis performing unit204then gives word class data representing words of identified word class for each procedural text, to the inference unit205.

The inference unit205specifies, on the basis of the identified word classes, a permutation of target terms or words selected from the words of identified word classes represented by the word class data, and refers to the permutation pointwise-mutual-information model stored in the model storage unit131via the communication unit202, to specify the likelihood of the specified permutation. Here, the target terms are assumed to be one argument and two predicates but are not limited to such examples.

If multiple permutations can be specified in one procedural text, the inference unit205sets a mean value determined by averaging the likelihoods of the permutations to be a definite likelihood of the procedural text. If only one permutation is specified in one procedural text, the likelihood of that permutation is the definite likelihood. The inference unit205gives definite likelihood data representing the definite likelihood of each procedural text to the ranking unit206. The definite likelihood here is also referred to as ranking likelihood.

The ranking unit206ranks procedural texts in accordance with the definite likelihoods represented by the definite likelihood data. For example, the ranking unit206ranks the procedural texts in descending order of definite likelihood represented by the definite likelihood data.

The information processing device200described above can be implemented by the computer120illustrated inFIG.2.

For example, the acquiring unit201, the procedural-text generating unit203, the morphological-analysis performing unit204, the inference unit205, and the ranking unit206can be implemented by the processor124loading the programs stored in the non-volatile memory121to the volatile memory122and executing these programs.

The communication unit202can be implemented by the NIC123.

FIG.5is a flowchart illustrating an operation for performing common sense inference by the information processing device200according to the second embodiment.

First, the acquiring unit201acquires step count data (step S20). The acquiring unit201then gives the step count data to the procedural-text generating unit203.

The procedural-text generating unit203refers to the candidate text data stored in the candidate-text storage unit130via the communication unit202to generate a procedural text that concatenates the same number of permutations of candidate texts as the step count represented by the step count data from the acquiring unit201(step S21). The procedural-text generating unit203then gives procedural text data representing procedural texts to the morphological-analysis performing unit204.

The morphological-analysis performing unit204performs morphological analysis on each of the procedural texts represented by the procedural text data to identify the word class of each of the words in each of the procedural texts (step S22). The morphological-analysis performing unit204then gives word class data representing words of identified word classes for each procedural text, to the inference unit205.

The inference unit205refers to the permutation pointwise-mutual-information model stored in the model storage unit131via the communication unit202to specify the permutations of one argument and two predicates for each procedural text from the words of identified word classes represented by the word class data, and specifies the likelihoods of the permutations. The inference unit205then sets the mean value of the likelihoods of the permutations that can be specified in a procedural text as a definite likelihood of the procedural text (step S22). The inference unit205gives definite likelihood data representing the definite likelihood of each procedural text to the ranking unit206.

The ranking unit206ranks the procedural texts in descending order of definite likelihood represented by the definite likelihood data (step S23). In this way, the procedural texts can be identified in descending order of the definite likelihoods.

As described above, according to the second embodiment, it is possible to identify procedural texts having high likelihoods in the procedural texts in accordance with the order of appearance of one term and two predicates.

The inference unit205uses the average likelihood of multiple permutations but alternatively, the average may be obtained by dividing by the number of words in the procedural text. The inference unit205may alternatively use the cosine distance of the tensors of the model for two words of the permutation of the question text and two words of the permutation of the procedural text.

Third Embodiment

FIG.6is a block diagram schematically illustrating a configuration of an information processing device300functioning as a learning device according to the third embodiment.

The information processing device300includes an acquiring unit301, a morphological-analysis performing unit302, a specifying unit303, a communication unit104, a generating unit305, and a first model storage unit307, and a second model storage unit306.

The communication unit104of the information processing device300according to the third embodiment is the same as the communication unit104of the information processing device100according to the first embodiment.

The acquiring unit301acquires first training data and second training data. The first training data and the second training data are text data including character strings. For example, the acquiring unit301may acquire the first training data and the second training data from another device via the communication unit104or may acquire the first training data and the second training data from a user or the like via an input unit (not illustrated). The acquiring unit301then gives the first training data and the second training data to the morphological-analysis performing unit302.

It is assumed that the first training data represents first character strings consisting of a character string constituting a question text and character strings constituting an answer text to the question text. In other words, the answer text to the question text includes two or more sentences and multiple steps.

It is also assumed that the second training data represents second character strings which are character strings constituting an answer text to a question text. In other words, the answer text to the question text includes two or more sentences and multiple steps.

The morphological-analysis performing unit302performs morphological analysis on the character strings represented by each of the first training data and the second training data to identify the word class of each of the words in the character strings.

The morphological-analysis performing unit302then gives first word class data representing words of identified word classes in the first character strings, to the specifying unit303and gives second word class data representing words of identified word classes in the second character strings, to the specifying unit303.

The specifying unit303specifies, on the basis of the identified word classes, combinations of first target terms or words selected from words of identified word classes represented by the first word class data. Here, the first target terms are assumed to be two arguments and one predicate but are not limited to such examples. The specifying unit303then gives combination data representing the specified combination to the generating unit305.

The specifying unit303also specifies, on the basis of the identified word classes, the permutations of second target terms or words selected from words of identified word classes represented by the second word class data. Here, the second target terms are assumed to be one argument and two predicates but are not limited to such examples. The specifying unit303then gives permutation data representing the specified permutations to the generating unit305.

The generating unit305connects to a corpus via the communication unit104and calculates combination pointwise mutual information, which is the pointwise mutual information in the corpus, of the combination of two arguments and one predicate represented by the combination data.

The combination pointwise mutual information is calculated, for example, by the following equation (4):

Here, vldenotes one predicate included in a combination represented by the combination data; wmdenotes one argument included in the combination represented by the combination data; and wndenotes the remaining argument included in the combination represented by the combination data.

P(vl) denotes the probability of appearance of the predicate vlor the number of predicate vlrelative to the total number of words in the corpus. P(wm) denotes the probability of appearance of the argument wmor the number of argument wmrelative to the total number of words in the corpus. P(wn) denotes the probability of appearance of the argument wnor the number of argument wnrelative to the total number of words in the corpus. P(vl, wm, wn) denotes the probability of appearance of the combination of the predicate vl, the argument wm, and the argument wnin the corpus, or is the number of texts including the combination of the predicate vl, the argument wm, and the argument wnrelative to the total number of words in the corpus.

As in the first embodiment, the generating unit305connects to a corpus via the communication unit104and calculates the combination pointwise mutual information, which is the pointwise mutual information in the corpus, of combinations of one argument and two predicates represented by the combination data.

The generating unit305then learns the combinations of two arguments and one predicate and the calculated combination pointwise mutual information to generate a combination pointwise-mutual-information model or a first trained model. The generate combination pointwise-mutual-information model is stored in the first model storage unit307. The combination pointwise-mutual-information model is, for example, a model in which the combination pointwise mutual information corresponding to combinations of one argument and two predicates is represented by a triaxial tensor.

The generating unit305learns the permutations of one argument and two predicates and the calculated permutation pointwise mutual information to generate a permutation pointwise-mutual-information model or a second trained model. The generated permutation pointwise-mutual-information model is stored in the second model storage unit308. The permutation pointwise-mutual-information model is, for example, a model in which the permutation pointwise mutual information corresponding to one argument and two predicates is represented by a triaxial tensor.

The first model storage unit307is a first storage unit that stores the combination pointwise-mutual-information model.

The second model storage unit308is a second storage unit that stores the permutation pointwise-mutual-information model.

The information processing device300illustrated inFIG.6can be implemented by the computer120illustrated inFIG.2.

For example, the acquiring unit301, the morphological-analysis performing unit302, the specifying unit303, and the generating unit305can be implemented by the processor124loading the programs stored in the non-volatile memory121to the volatile memory122and executing these programs.

The first model storage unit307and the second model storage unit308can be implemented by the non-volatile memory121.

The communication unit104can be implemented by the NIC123.

The information processing device300may be implemented by a processing circuit or may be implemented by software, firmware, or a combination of these. The processing circuit may be a single circuit or a composite circuit.

In other words, the information processing device300can be implemented by processing circuitry.

Since the operation of generating a permutation pointwise-mutual-information model from the second training data in the third embodiment is the same as that in the first embodiment, here, the operation of generating a combination pointwise-mutual-information model from the first training data is explained.

FIG.7is a flowchart illustrating an operation of learning a combination pointwise-mutual-information model by the information processing device300according to the third embodiment.

First, the acquiring unit301acquires first training data (step S30). The acquiring unit301then gives the first training data to the morphological-analysis performing unit302.

The morphological-analysis performing unit302performs morphological analysis on the character strings represented by the first training data to identify the word classes of the words in the character strings (step S31). The morphological-analysis performing unit302then gives first word class data representing the words of identified word classes to the specifying unit303.

The specifying unit303determines whether or not the words of identified word classes represented by the first word class data include one or more predicates (step S32). If one or more predicates are included (Yes in step S32), the process proceeds to step S33, and if no predicates are included (No in step S32), the process ends.

In step S33, the specifying unit303specifies a combination consisting of two arguments and one predicate in the words of identified word classes represented by the word class data. The combination specified here is a combination for which combination pointwise mutual information has not yet been calculated in step S34. The specifying unit303then gives combination data representing the specified combination to the generating unit305.

The generating unit305connects to a corpus via the communication unit104and calculates combination pointwise mutual information, which is the pointwise mutual information in the corpus, of the combination of two arguments and one predicate represented by the combination data (step S34). The generating unit305then learns two arguments, one predicate, and the calculated combination pointwise mutual information, associates these with each other, and registers these in the combination pointwise-mutual-information model stored in the first model storage unit307.

Next, the specifying unit303determines whether or not there is still a combination for which the combination pointwise mutual information has not yet been calculated (step S35). If such a combination remains (Yes in step S35), the process returns to step S33, and if no such combination remains (No in step S35), the process ends.

As described above, according to the third embodiment, pointwise mutual information corresponding to a combination of two arguments and one predicate and pointwise mutual information corresponding to the order in which one argument and two predicates appear can be accumulated as a trained model.

In the third embodiment, the generating unit305is connected to an external corpus via the communication unit104, but the third embodiment is not limited to such an example. For example, a corpus may be stored in the first model storage unit307, the second model storage unit309, or another storage unit not illustrated. In such a case, the communication unit104is not needed.

In the third embodiment, the first model storage unit307and the second model storage unit308are provided in the information processing device300, but the third embodiment is not limited to such an example. For example, the generating unit305may store at least one of the combination pointwise-mutual-information model and the permutation pointwise-mutual-information model in a storage unit (not illustrated) provided in another device via the communication unit104. In such a case, either the first model storage unit307or the second model storage unit308provided in the information processing device300is not needed.

Fourth Embodiment

FIG.8is a block diagram schematically illustrating a configuration of an information processing device400functioning as an inference device according to the fourth embodiment.

The information processing device400includes an acquiring unit401, a communication unit402, a procedural-text generating unit403, a morphological-analysis performing unit404, an inference unit405, and a ranking unit406.

The inference device according to the fourth embodiment is a device that makes an inference by referring to a combination pointwise-mutual-information model and a permutation pointwise-mutual-information model.

The acquiring unit401acquires question text data and step count data. The question text data is text data representing the character string of a question text. The step count data is data representing the number of steps of answering a question text represented by the question text data. For example, the acquiring unit401may acquire the question text data and the step count data from another device via the communication unit402or may acquire the question text data and the step count data via an input unit (not illustrated). Here, the step count is two or more. Thus, the acquiring unit401acquires the question text and a step count of two or more for answering the question text.

The acquiring unit401then gives the question text data and the step count data to the procedural-text generating unit403.

The communication unit402communicates with other devices. Here, the communication unit402can communicate with, for example, a server on the Internet to receive data from a candidate-text storage unit432, a first model storage unit433, or a second model storage unit434provided in the server.

Here, the candidate-text storage unit432stores candidate text data representing candidate texts to be candidates of an answer to the question text.

The first model storage unit433stores a combination pointwise-mutual-information model generated through the same operation as that in the third embodiment as a first trained model.

The second model storage unit434stores a permutation pointwise-mutual-information model generated through the same operation as that in the first embodiment as a second trained model.

The procedural-text generating unit403refers to the candidate text data stored in the candidate-text storage unit432via the communication unit402to extract the same number of candidate texts as the step count represented by the step count data from the acquiring unit401, and concatenates two or more extracted candidate texts to generate multiple procedural texts. In other words, each of the procedural texts includes two or more candidate texts.

Furthermore, the procedural-text generating unit403generates question-answering procedural texts by concatenating the question texts represented by the question text data in front of the generated procedural texts.

For example, if a question text represented by the question text data is “To cook rice” and the procedural text is “Measure rice into inner pot. Rince rice,” the question-answering procedural text is “To cook rice. Measure rice into inner pot. Rince rice.”

The procedural-text generating unit403gives question-answering procedural-text data representing question-answering procedural texts to the morphological-analysis performing unit404.

The morphological-analysis performing unit404performs morphological analysis on each of the question-answering procedural texts represented by the question-answering procedural-text data to identify the word class of each of the words in each of the question-answering procedural texts.

The morphological-analysis performing unit404then gives first word class data representing the words of identified word classes for each question-answering procedural text, to the inference unit405.

The inference unit405specifies, on the basis of the identified word classes, a combination of first target terms or words selected from the words of identified word classes represented by the first word class data, and refers to the combination pointwise-mutual-information model stored in the first model storage unit433via the communication unit402to specify the likelihood of the combination. The first target terms are assumed to be two arguments and one predicate but are not limited to such examples. When multiple combinations can be specified in one quest ion-answering procedural text, the inference unit405sets a mean value determined by averaging the likelihoods of the combinations that can be specified in the question-answering procedural text, as a definite likelihood of the question-answering procedural text. When only one combination is specified in one question-answering procedural text, the likelihood of the combination is defined as the definite likelihood. The definite likelihood specified here is also referred to as first likelihood.

Next, the inference unit405extracts question-answering procedural texts by narrowing down the procedural texts with the definite likelihood or first likelihood. For example, the inference unit405extracts a predetermined number of question-answering procedural texts in descending order of the definite likelihood or first likelihood. The inference unit405then generates target procedural texts by removing the question texts from the extracted question-answering procedural texts. The inference unit405then generates second word class data representing words of identified word classes included in each of the generated target procedural texts.

Furthermore, the inference unit405specifies, on the basis of the identified word classes, the permutation of second target terms or words of predetermined word classes in the words of identified word classes represented by the second word class data. The inference unit405then refers to the permutation pointwise-mutual-information model stored in the second model storage unit434via the communication unit402to specify the likelihood of the permutation of the second target terms. Here, the second target terms are assumed to be one argument and two predicates but are not limited to such examples.

When multiple permutations can be specified in one procedural text, the inference unit405sets a mean value determined by averaging the likelihoods of the permutations as a definite likelihood of the procedural text. When only one permutation can be specified in one procedural text, the likelihood of the permutation is the definite likelihood. The inference unit405gives definite likelihood data representing the definite likelihood of each procedural text to the ranking unit406. The definite likelihood specified here is also referred to as ranking likelihood.

The ranking unit406ranks the procedural texts in accordance with the definite likelihoods represented by the definite likelihood data. For example, the ranking unit406ranks the procedural texts in descending order of the definite likelihoods represented by the definite likelihood data.

The information processing device400described above can also be implemented by the computer120illustrated inFIG.2.

For example, the acquiring unit401, the procedural-text generating unit403, the morphological-analysis performing unit404, the inference unit405, and the ranking unit406can be implemented by the processor124loading the programs stored in the non-volatile memory121to the volatile memory122and executing these programs.

The communication unit402can be implemented by the NIC123.

FIG.9is a flowchart illustrating an operation for performing a common sense inference by the information processing device400according to the fourth embodiment.

First, the acquiring unit401acquires question text data and step count data (step S40). The acquiring unit401then gives the question text data and the step count data to the procedural-text generating unit403.

The procedural-text generating unit.403refers to the candidate text data stored in the candidate-text storage unit432via the communication unit402to generate a procedural text that concatenates the same number of permutations of candidate texts as the step count represented by the step count data from the acquiring unit401, and concatenates a question text represented by the question text data to the front of the procedural text to generate a question-answering procedural text (step S41). The procedural-text generating unit403then gives question-answering procedural-text data representing question-answering procedural texts to the morphological-analysis performing unit404.

The morphological-analysis performing unit404performs morphological analysis on each of the question-answering procedural texts represented by the question-answering procedural-text data to identify the word class of each of the words included in the question-answering procedural texts (step S42). The morphological-analysis performing unit404then gives first word class data representing the words of identified word classes for each question-answering procedural text, to the inference unit405.

The inference unit405refers to the combination pointwise-mutual-information model stored in the first model storage unit433via the communication unit402to specify combinations of two arguments and one predicate for each question-answering procedural text in the words of identified word classes represented by the first word class data, and specify the likelihood of the combination. The inference unit405then sets the mean value of the likelihoods of the combinations that can be specified from one question-answering procedural text as the definite likelihood of the question-answering procedural text (step S43).

The inference unit405narrows down the question-answering procedural texts in descending order of the definite likelihoods specified in step S43(step S44). For example, the inference unit405performs the narrowing by extracting a predetermined number of question-answering procedural texts in descending order of the definite likelihoods specified in step S43. The inference unit405then deletes the words in question texts from the words of identified word classes corresponding to the extracted question-answering procedural texts in the word class data, and specifies the procedural texts resulting from deleting the question texts from the specified question-answering procedural texts. The inference unit405generates, for each of the specified procedural texts, second word class data representing words of identified word classes included in the corresponding procedural text.

Next, the inference unit405refers to the permutation pointwise-mutual-information model stored in the second model storage unit434via the communication unit402to specify the permutations of one argument and two predicates for each of the procedural texts in the words of identified word classes represented by the second word class data, and specify the likelihoods of the permutations. The inference unit405then sets the mean value of the likelihoods of the permutations that can be specified in a procedural text as a definite likelihood of the procedural text (step S45). The inference unit405gives the definite likelihood data representing the definite likelihood of each procedural text specified in step S45to the ranking unit406.

The ranking unit406ranks the procedural texts in descending order of the definite likelihoods represented by the definite likelihood data (step S46). In this way, the procedural texts can be identified in descending order of the definite likelihoods.

As described above, according to the fourth embodiment, it is possible to specify a procedural text of a high likelihood from question-answering procedural texts in accordance with the order of appearance of two arguments and one predicate, and to identify a procedural text of a high likelihood in the specified procedural texts in accordance with the order of appearance of one argument and two predicates.

Fifth Embodiment

FIG.10is a block diagram schematically illustrating a configuration of an information processing device500functioning as an inference device according to the fifth embodiment.

The information processing device500includes an acquiring unit401, a communication unit502, a procedural-text generating unit403, a morphological-analysis performing unit404, a first inference unit505, a ranking unit506, and a second inference unit507.

The inference device according to the fifth embodiment is a device that makes an inference by referring to a combination pointwise-mutual-information model, a permutation pointwise-mutual-information model, and a trained model other than the combination pointwise-mutual-information model and the permutation pointwise-mutual-information model.

The acquiring unit401, the procedural-text generating unit403, and the morphological-analysis performing unit404of the information processing device500according to the fifth embodiment are respectively the same as the acquiring unit401, the procedure-statement generating unit403, and the morphological-analysis performing unit404of the information processing device400according to the fourth embodiment.

The communication unit502communicates with other devices. Here, the communication unit502can communicate with, for example, a server on the Internet to receive data from a candidate-text storage unit432, a first model storage unit433, a second model storage unit434, or an alternate-model storage unit535provided in the server.

Here, the candidate-text storage unit432, the first model storage unit433, and the second model storage unit434according to the fifth embodiment are respectively the same as the candidate-text storage unit432, the first model storage unit433, and the second model storage unit434according to the fourth embodiment.

The alternate-model storage unit535stores an alternate model or a trained model that has been trained by a theory different from the combination pointwise-mutual-information model and the permutation pointwise-mutual-information model. Examples of alternate models include trained models based on known theories such as trained models based on Bidirectional Encoder Representations from Transformers (BERT), trained models based on a Robustly Optimized BERT Pretraining Approach (RoBERTa), trained models based on Generative Pre-trained Transformer 2 (GPT-2), trained models based on Text-to-Text Transfer Transformer (TS), and trained models based on Turing Natural Language Generation (NLG) or Generative Pre-trained Transformer 3 (GPT-3).

Here, the trained model based on BERT is used as the alternate model. The alternate model is also referred to as a target trained model.

Similar to the inference unit405according to the fourth embodiment, the first inference unit505uses the combination pointwise-mutual-information model stored in the first model storage unit433and the permutation pointwise-mutual-information model stored in the second model storage unit434to calculate the definite likelihood for each procedural text. The first inference unit505then specifies a predetermined number of procedural texts in descending order of the calculated definite likelihoods, generates narrowed procedural text data representing the specified procedural texts, and gives the narrowed procedural text data to the second inference unit507.

For example, the first inference unit505specifies, on the basis of the word classes identified by the morphological-analysis performing unit404, a combination of first target terms or words selected from question-answering procedural texts. The first inference unit505refers to the combination pointwise-mutual-information model stored in the first model storage unit433to calculate the likelihood of the specified combination to specify a first likelihood or the likelihood of each procedural text.

Furthermore, the first inference unit505deletes question texts from the question-answering procedural texts extracted by narrowing down the procedural texts with the first likelihoods to generate first target procedural texts. The first inference unit505then specifies, on the basis of the word classes identified by the morphological-analysis performing unit404, a permutation of second target terms or words selected from each of the first target procedural texts, and refers to the permutation pointwise-mutual-information model stored in the second model storage unit434to specify a second likelihood or the likelihood of each of the first target procedural texts by calculating the likelihood of the specified permutation. The first inference unit505narrows down the first target procedural texts with the second likelihoods to extract second target procedural texts.

Finally, the first inference unit505generates narrowed procedural text data representing the extracted second target procedural texts.

The second inference unit507refers to the alternate model stored in the alternate-model storage unit535and specifies the ranking likelihood or the likelihood of each of the second target procedural texts.

For example, the second inference unit507refers to the alternate model stored in the alternate-model storage unit535via the communication unit502and calculates the likelihood of the correctness of the context of each procedural text represented by the narrowed procedural text data. In the present embodiment, the average likelihood of a word sequence in a question-answering procedural text is used to determine the correctness of the context. The second inference unit507then generates likelihood data representing the calculated likelihood for each procedural text and gives the likelihood data to the ranking unit506. The likelihood represented by the likelihood data here is the ranking likelihood.

The ranking unit506ranks multiple procedural texts in accordance with the likelihoods represented by the likelihood data. Specifically, the ranking unit506ranks the procedural texts in descending order of likelihoods represented by the likelihood data.

The information processing device500described above can be implemented by the computer120illustrated inFIG.2.

For example, the acquiring unit401, the procedural-text generating unit403, the morphological-analysis performing unit404, the first inference unit505, the ranking unit506, and the second inference unit507can be implemented by the processor124loading the programs stored in the non-volatile memory121to the volatile memory122and executing these programs.

The communication unit502can be implemented by the NIC123.

FIG.11is a flowchart illustrating an operation for performing a common sense inference of the information processing device500according to the fifth embodiment.

First, the acquiring unit401acquires question text data and step count data (step S50). The acquiring unit401then gives the question text data and the step count data to the procedural-text generating unit403.

The procedural-text generating unit403refers to the candidate text data stored in the candidate-text storage unit432via the communication unit502to generate a procedural text that concatenates the same number of permutations of candidate texts as the step count represented by the step count data from the acquiring unit401, and concatenates a question text represented by the question text data to the front of the procedural text to generate a question-answering procedural text (step S51). The procedural-text generating unit403then gives question-answering procedural-text data representing question-answering procedural texts to the morphological-analysis performing unit404.

The morphological-analysis performing unit404performs morphological analysis on each of the question-answering procedural texts represented by the question-answering procedural-text data to identify the word class of each of the words included in the question-answering procedural texts (step S52). The morphological-analysis performing unit404then gives first word class data representing the words of identified word classes for each question-answering procedural text to the first inference unit505.

The first inference unit505refers to the combination pointwise-mutual-information model stored in the first model storage unit433via the communication unit502to specify combinations of two arguments and one predicate for each question-answering procedural text in the words of identified word classes represented by the first word class data, and specifies the likelihood of the combination. The first inference unit505then sets the mean value by averaging the likelihoods of the combinations that can be specified from one question-answering procedural text as the definite likelihood of the question-answering procedural text (step S53).

The first inference unit505narrows down the question-answering procedural texts in descending order of the definite likelihoods specified in step S53(step S54). For example, the first inference unit505extracts a predetermined number of question-answering procedural texts in descending order of the definite likelihoods specified in step S53. The first inference unit505deletes the words in question texts from the words of identified word classes corresponding to the extracted question-answering procedural texts in the word class data, and specifies the procedural texts resulting from deleting the question texts from the specified question-answering procedural texts. The first inference unit505then generates, for each of the specified procedural texts, second word class data representing words of identified word classes included in the corresponding procedural text.

Next, the first inference unit505refers to the permutation pointwise-mutual-information model stored in the second model storage unit434via the communication unit502to specify the permutations of one argument and two predicates for each of the procedural texts in the words of identified word classes represented by the second word class data, and specifies the likelihoods of the permutations. The first inference unit505then sets the mean value by averaging the likelihoods of the permutations that can be specified in a procedural text as a definite likelihood of the procedural text (step S55).

Next, the first inference unit505narrows down the procedural texts in descending order of the definite likelihoods calculated in step S55(step S56). For example, the first inference unit505extracts a predetermined number of procedural texts in descending order of the definite likelihoods calculated in step S55. The first inference unit505then generates narrowed procedural text data indicating the extracted procedural texts and gives the narrowed procedural text data to the second inference unit507.

The second inference unit507refers to the alternate model stored in the alternate-model storage unit535via the communication unit502and calculates the likelihood of the correctness of the context of each procedural text represented by the narrowed procedural text data (step S57). The second inference unit507then generates likelihood data representing the calculated likelihood for each procedural text and gives the likelihood data to the ranking unit506.

The ranking unit506ranks the procedural texts in descending order of the likelihoods represented by the likelihood data (step S57). In this way, the procedural texts can be identified in descending order of likelihood.

As described above, according to the fifth embodiment, it is possible to identify procedural texts with high likelihoods in the question-answering procedural texts in accordance with the order of appearance of two arguments and one predicate and narrow down, in the identified procedural texts, the procedural texts with high likelihoods in accordance with the order of appearance of one argument and two predicates. Then, by making an inference about the likelihoods of the narrowed-down procedural texts through, for example, BERT, the processing load can be reduced even if a theory with a heavy processing load is used.