Presentation is loading. Please wait.

Presentation is loading. Please wait.

Cognitive Model of Time and Analysis of Natural Language Texts Naidenova, X.A., Garina, M.I.

Similar presentations


Presentation on theme: "Cognitive Model of Time and Analysis of Natural Language Texts Naidenova, X.A., Garina, M.I."— Presentation transcript:

1 Cognitive Model of Time and Analysis of Natural Language Texts Naidenova, X.A., Garina, M.I.

2 Cognitive model of time Cognitive model of time includes: The units of time ( year, month, spring, minute ); the time intervals and their properties: the beginning, the end, duration, without beginning (opened in the past), without end (opened in the future), consisting of points; Environment: nearest past, nearest future (about noon, soon after the beginning/the end, toward the evening); Various relations between units and intervals: coincidence, contact, presedence, going after, intersection, inclusion, remoteness into the past/future time; Degree of relations: the measures of remoteness, intersection and so on; Comparison relations of interval duration: longer, less for long, shorter and so on; Uncertain (fuzzy) relations: considerably later, once, early in the morning and so on;

3 Main cognitive constructions Event (can be empty) time interval; Time interval ::= (the beginning --- the end) / unit of time/ a set of units of time; a moment of time is the particular case of interval; The beginning ::= the date/event; the end::= the date/event; Interval has the duration; Event is associated with time interval. But the very moment of time can be an event :«September began», «Days go»; Time interval can be expressed via some events, for example, at dawn, to the first volleys of artillery, long before the first sun rays.

4 The Basic Cognitive Model of Time Periodicity EventTime of eventDuration Methods The dateUnit of timeInterval The beginningThe end Event The date Unit of time Interval Time of event Duration Time of event Duration

5 The Property of Cognitive Model of Time Obviously, this diagram is recursive, i.e., an event is associated with the time interval, and a time interval can be expressed via some events, for example: at dawn, to the first volleys of artillery, long before the first sun rays.

6 Methods Computation Rules for DURATION: а) as the difference between the end and the beginning with the precise time markers (the dates); б) as the time interval between events: since to ; в) as a set of time units (900 days). Rules for demonstrating the truthfulnes of different relations between time intervals: sequence (which is earlier, which is later, which will be, which is already past), simultaneity, inclusion into one and the same time interval, intersection, contact and so on.

7 Methods as meta-knowledge Methods are natural rules for analyzing the relationships between time units/intervals; Methods include both computations and implicative assertions of the general kind: E1,T.end < E2, T.begin E1 R E2, where E1 and E2 are events, E.T is interval associated with event E, T.end and T.begin are the end and beginning of interval T, respectively, and R is the precedence relation; «T.begin T.end; T.end T.begin»;

8 Properties of Events Events can be indeterminate (fuzzy) in the time (considerably later, once upon a time); Events can flow in the time rapidly, slowly; Periodic events can be frequent or rare; The temporary properties of events can be both objective and subjective (estimated).

9 It is still necessary to consider A set of events can be associated with only one time interval ; An event can be expressed by both only one word and a set of proposals (maybe only one proposal); An event and the time interval associated with it can be in different proposals;

10 It is still necessary to consider It is possible that an active agent (including temporary moment) cannot be determined without the aid of referential relation ; There are the events attached (by default) to the time intervals (dawn, sunset, school- leaving ball, dinner, supper, breakfast, the beginning of workday).

11 The link of cognitive model of time with NLs The cognitive model of time does not depend on language, but it is tuned into different natural languages. For this goal, the following levels of natural language are considered: lexical, morphological, and syntactic ones. Questions of constructing a translator of the cognitive model of time (its elements and the generalized assertions (meta - knowledge)) into language expressions for a given natural language and vice versa are examined. Translator can be built as a trained system that learns by specially constructed phrases.

12 The Lexical Level A special case of time interval is the name of time unit Example: TI = { century, year, month, twenty-four hours, the morning, day, evening, the night, January, February, March, April, May, June, minute, second, winter, summer …}

13 Relationships between lexical units of NL Classification («is-a»), composition («concsist- of»), part-whole, occurring in cycles, inclusion, sequence: Year is (winter, spring, summer, autumn); Occurring in cycles: winter of one year follows after autumn of previous year; Sequence: spring is after winter; «Part-Whole»: minute is a part of hour; Composition: twenty-four hours consist of night and day;

14

15 Explanations to the diagram The relation of classification is shown with the aid of triangle connections while the relation of composition - by pointer with the rhomb. If the relation of composition is determined between the intervals of upper level, then it is determined between the interval- descendants (for example, June consists of twenty-four hours). Specific dimensionality can be determined only for the connections of the lower level (it cannot be said how many twenty-four hours year generally consists of, month generally consists of, but it can be said, how many twenty-four hours leap year consists of, month consists of, January consists of, etc)

16 Lexical level of time relationships. Table: « Time of event » (for Russian Language) from «Multidimensionality of the time ». Elkin, S. V. et al.) 1 Event2 Duration of the event, durability 3 Long duration, short duration, short- term, momentary, transitory Repetition of the eventProcess consisting of several different events Event series Multiple repetition of one and the same event Daily, every week It is quarterly, monthly, Yearly OnceOnce only, it is single-time Time before the eventBefore, in advance, in good time, previously, before the appointed time, it is preliminary, it is premature, on the threshold of, it is earlier than, long before, thus far not, not in a long time, recently, as long as, the day before Time after the event Later, afterward, it is later, then, after, hence, hence-forward, forth, in future, from now on, after all, immediately afterward, further, when Association of the event with the time In ones life (from birth), originally, while

17 Indeterminate time Affirmative time: sometimes, someday, in the course of time, then, once; Negative time: never

18 Temporary pretexts The approximate classification of Russian temporary pretexts has been given by Kreydlin, G.E. Time through the prism of temporary pretexts // The logical analysis of the language: Language and time. M p.

19 RelationPretextExampleTemporary marker, the event Simultaneity Extent Duration For, During For entire trip he said nothing The time interval is attached to the event (trip) PrecedenceApproximatelyWe awaited approximately to midnight Temporary marker: midnight; Time: the indeterminate half-interval.

20 Syntactic Level RelationStructureSyntactic diagram Role in the sentence Going afterImmediately afterward /, Adverb with the pretext «afterward» /, Adverbial modifier of time. Example: Immediately after wedding and parting words of parents. InclusionIncluding Verbal Adverb Adverbial modifier of time. Example: Including 2010

21 Text processing Text processing system consists of Cognitive models of time and events that oriented to a given domain application and the goals of text processing; Translater that is adjusted to a given NL; Block of plausible (commonsense) reasoning which infers consequences from established temporary relations between events in the text by means of meta- knowledge of cognitive models; Dialogue Syntactical Analyzer for a given NL; Block of control or operational subsystem of the translater.

22 Cognitive Model Of Time Cognitive Model Of Event Text Plausible Inferrence Translator, adjusted to NL Syntactical Analyzer Base of extracted events and time relations between them Control

23 Text processing Text interacts with the Translator and Syntactical Analyzer; As a result, events, their time moments or interval are extracted, and then the conclusions about temporary relations between the events are inferred.

24 The work of Translator (1) Translator first searches for the supporting (key) words (temporary markers), which are connected with the expression of time in the text. Then translator, using lexical and syntactic models, attempts to determine the events, associated with the chosen time markers. If it is necessary, then turning to Syntactic Analyzer follows.

25 The work of translator (2) Translator can repeatedly be turned first to the text or first to the cognitive model, then to the syntactic analyzer in order purposefully to search for the required (according to the rules of cognitive model) linguistic constructions.

26 Formation of the Base of Events Hypotheses about the events and the temporary supporting moments are erected as the list of the possible facts, extracted from the text. The Base of Events is filled up with the copies of events with their time characteristics.

27 The work of Block of Plausible Reasoning The block of plausible reasoning derives all consequences of the discovered facts (events, their properties, the relations between them).

28 Example of extracting events and time of events from the text An example of the text analysis has been given from the narrative of V. Nekrasov The entrenchments of Stalingrad. This example shows what we will have as a result of the event-temporary text analysis with the use of cognitive models of time and events

29 Sentence 1 The number of sentence EventTime intervalInferred information 1I do not recollect AutumnAutumn consists of «September, October, November».

30 Sentence 2 The number of sentence EventTime intervalInferred information 2September passed SeptemberIt precedes October; consequently, began October. Time interval «September» is an event. Predicate is expressed by the verb of passed time, whose semantics speaks that the time interval is finished, it left into the past. It is derived from the cognitive model of time that October goes after September, next month of autumn.

31 Sentence 3 The number of sentence EventTime intervalInferred information 3 Event 1: Fish laps in the Volga; Event 2: Circles disperse over the surface of water. In the mornings Each day in the morning; October ; Autumn.

32 Sentence 6 The number of sentence EventTime intervalInferred data 6 It is tender = Left shore of the Volga is tender At dawn; To the first volleys of the artillery; At dawn = early in the morning; To (before) the first volleys of the artillery; Event = the first volleys of the artillery; 6 First volleys of the artillery At dawn;Early in the morning; October; Autumn.

33 Sentence 8 The number of sentence EventTime intervalInferred information 8 Event: Х lasts; Х = the fog For a whileFor a while; Early in the morning. In this proposal there is no subject and therefore there is no acting agent. We establish it with the aid of the reference (analysis of the previous proposal).

34 Sentence 9 The number of sentence EventTime intervalInferred information 9 Long-range gun shoots Long before the first sun rays 9 Event: First sun rays At dawnEarly in the morning; October; Autumn. In proposal 9 there is no explicit indication of moment of time. But adverbial modifier of time «before the first sun rays» is associated with dawn, and dawn – with morning. Thats why we extract the event «the first sun rays» and associate it with « early in the morning ».

35 Sentences 11 and 12 The number of sentence EventTime intervalInferred information 11 The day begins The dayDay comes after morning; The beginning of the day. 12 The « frame » appears At seven oclock Seven hours of the morning; Beginning of the day.

36 Sentence 19 The number of sentence EventTime intervalInferred information 19 It will determineEntire day 19 It = the first ten of aircrafts Entire dayEntire day = from the morning to the evening Sentence19 «It will determine entire day» requires the returning to the previous sentence in order to assiciate the word « it » with « the first ten of aircrafts ». This action requires the complete syntactic analysis of sentence 18.

37 Sentence 20 The number of sentence EventTime intervalInferred information 20 Event 1: They will bury those killed; Event 2: repair the damaged guns; Event 3 : dig new slots and mud-huts; Entire nightAfter day; From the evening to the morning; From the sunset to the dawn;

38 Explanations to sentence 20 In proposal 20, we separate the fragment connected with the keywords entire night. Subject and predicate determine event we learn. However time interval relates to direct object: «We learn, in what section entire night they will bury those killed, repair the damaged machine guns and guns, dig new slots and mud-huts».

39 Some observations The dialogue between the cognitive model of time, the translator and the syntactic analyzer occurs. The completeness and the accuracy of the extracted knowledge depends on the cognitive model of time, its completeness and accuracy. We rested on the time marks. But it is possible to make events to be key markers.

40 What is necessary to make? (1) 1. To build Cognitive Model of Time as completely as possible including all abstract elements, relations and methods. It is also necessary to take into account the uncertainty of time intervals.

41 What is necessary to make? (2) 1. To build the Cognitive Model of Event. 2. Cognitive elements of model are: FACT, PROCESS, ACTION, RESULT, SUBJECT, OBJECT, PLACE of EVENT, TIME of EVENT, CAUSAL LINKS between EVENTS, PROPERTY of OBJECT (SUBJECT). 3. To refine this model through the knowledge of a concrete domain application (business, finances). To build model of all possible events in a given domain application with a mechanism of plausible inference over this models of events. To build model of all possible events in a given domain application with a mechanism of plausible inference over this models of events.

42 What is necessary to make? (3) After the work on the cognitive models it is possible to be turned to creating the translator. It will be necessary to determine in sentences the parts of speech (subject, predicate, object, adverbial modifiers). It is necessary to recognize different kinds of sentences. After the work on the cognitive models it is possible to be turned to creating the translator. It will be necessary to determine in sentences the parts of speech (subject, predicate, object, adverbial modifiers). It is necessary to recognize different kinds of sentences. The main thing, that the analysis of sentences is governed with the aid of the cognitive models. The conclusions are done at the level of cognitive models and the concrete queries to the syntactic analyzer can be formed via cognitive models. The main thing, that the analysis of sentences is governed with the aid of the cognitive models. The conclusions are done at the level of cognitive models and the concrete queries to the syntactic analyzer can be formed via cognitive models.

43 Thanks for the attention


Download ppt "Cognitive Model of Time and Analysis of Natural Language Texts Naidenova, X.A., Garina, M.I."

Similar presentations


Ads by Google