• Journal of Internet Computing and Services
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• v.12 no.5
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• pp.73-85
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• 2011

Lots of valuable textual information is used to extract relations between named entities from literature. Composite kernel approach is proposed in this paper. The composite kernel approach calculates similarities based on the following information:(1) Phrase structure in convolution parse tree kernel that has shown encouraging results. (2) Predicate-argument structure patterns. In other words, the approach deals with syntactic structure as well as semantic structure using a reciprocal method. The proposed approach was evaluated using various types of test collections and it showed the better performance compared with those of previous approach using only information from syntactic structures. In addition, it showed the better performance than those of the state of the art approach.

• Language and Information
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• v.20 no.1
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• pp.51-71
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• 2016

The status of the Korean morphological marker '-e ci' has been controversial whether it is a passive marker, an anticausative marker, or a passive/anticausative marker. However, the previous approaches that tried to classify '-e ci' constructions based on the syntactic verb classes (i.e. intransitive or transitive) were short of explaining the properties of the constructions. In this study, the '-e ci' constructions were distinguished based on agentivity, following Levin & Rappaport Hovav (1995) and Alexiadou et al. (2006). Moreover, how the verbal root meaning is associated with the passive/anticausative construction was investigated by means of Distributed Morphology (DM) (Embick 2010; Marantz 1997). I argued that the morphological marker '-e ci' is the instantiation of the absence of external arguments. With respect to the behavior of the Korean '-e ci' constructions with the semantics of each verbal root class, I found out that the '-e ci' constructions can form passives with the verbal roots that require the external arguments; whereas, the anticausatives cannot be formed with the roots that necessarily require the agentive arguments. However, contrary to the previous arguments that '-e ci' passives can be only formed with transitive verbs, it is discovered that non-agentive transitive roots do form anticausatives. Moreover, I argued that there are two types of the anticausatives - zero and '-e ci' anticausatives. Since the valency reduction is marked by the non-active voice morphology, the zero anticausatives appear only with the roots that do not require external arguments. The different '-e ci' constructions (passives, '-e ci', and zero anticausatives) are represented by the distinct syntactic structures. I proposed that the morphological similarity between the passives and the '-e ci' anticausatives is due to the presence of VoiceP, which introduces the external arguments. Moreover, the lack of the voice morphology in the zero anticausatives is explained by the absence of the VoiceP.

• Korean Journal of Cognitive Science
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• v.13 no.1
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• pp.41-51
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• 2002

In this paper, I describe a knowledge-based question-answering system and significance of the system with a view to constructing a fact database. The knowledge-based system takes advantage of existing NLP-resources such as conceptual structures of ontologies along with morphotogical, syntactic and semantic analysis. The use of conceptual structures allows us to select right answers through inferences basically made by expansions of concepts. However, the work of constructing factual knowledge requires a great amount of acquisition time in large-scale applications because of the nature of human interference. This is why the procedure of acquiring factual knowledge cannot be fully automated. Apart from efficiency considerations. the knowledge-based system deserves serious consideration, I point out benefits of the system and describe the whole procedure of building the system in terms of a fact database.

• The Journal of Korean Association of Computer Education
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• v.18 no.4
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• pp.63-70
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• 2015

Program source code is a set of complex syntactic information which are expressed in text forms, and contains complex logical structures. Structural and logical complexity inside source code become barriers in applying visualization techniques shown in traditional big-data approaches when the volume of source code become over ten-thousand lines of code. This paper suggests a procedure for making visualization of structural characteristics in source code. For this purpose, this paper defines internal data structures as well as inter-procedural relationships among functions. The paper also suggests a means of outlining the structural characteristics of source code by visualizing the source codes with network forms The result of the research work can be used as a means of controling and understanding the massive volume of source code.

• Language and Information
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• v.2 no.2
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• pp.155-183
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• 1998

The purpose of this paper is to explore the syntactic criteria for determining a secondary predicates as a predicate modifier or a conjunction, and to formalize the semantic aspects of the [-ke] structure as a predicate in Korean. Syntactically, the [-ke] structure is considered to be a secondary predicate when the shared arguments appear in both the [-ke] structure and the main verb structure. On the other hand, if they do not appear in both structures, the [-ke] structure is considered to be a connective element. Semantically the [-ke] structure has numerous aspects such as depictives, resultatives, objectivity, and emphasis. The depictives of the secondary predicate can be formalize as $p{\wedge}q$ where p represents a propositional expression of the secondary predicate and q is a propositional expression of the main verb. Resultatives have the logical form $q{\rightarrow}{\Box}p$, because the consequence has to always be true. However, objectivity has the logical form $q{\rightarrow}{\diamondsuit}p$, because the consequence can be either true or false. Emphasis is represented as $q{\rightarrow}p{\uparrow}$ because the secondary predicate represents the polarity of the event.

• Journal of KIISE:Computing Practices and Letters
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• v.6 no.3
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• pp.364-372
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• 2000

Subcategorization, defining dependency relation between predicates and their complements, is an important source of knowledge for resolving syntactic and semantic ambiguities arising in analyzing sentences. This paper describes a Korean subcategorization dictionary, particularly annotated with semantic roles of complements coupled with thesaural semantic hierarchy as well as syntactic dependencies. For annotating roles, we defined 25 semantic roles associated with surface case markers that can be used to derive semantic structures directly from syntactic ones. In addition, we used more than 120,000 entries of thesaurus to specify concept markers of noun complements, and also used 47 and 17 predicate patterns for verbs and adjectives, respectively, to express dependency relation between predicates and their complements. Using a full-fledged thesaurus for specifying concept markers makes it possible to build an effective selectional restriction mechanism coupled with the subcategorization dictionary, and using the standard predicate patterns for specifying dependency relations makes it possible to avoid inconsistency in the results and to reduce the costs for constructing the dictionary. On the bases of these, we built a Korean subcategorization dictionary for frequently used 13,000 predicates found in corpora with the aid of a tool specially designed to support this task. An experimental result shows that this dictionary can provide 72.7% of predicates in corpora with appropriate subcategorization information.

• Journal of the Korea Society of Computer and Information
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• v.25 no.11
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• pp.27-40
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• 2020

In this paper, we investigate the correlation between the amount of English sentences that Korean English learners (L2ers) are exposed to and their sentence processing patterns by examining what Long Short-Term Memory (LSTM) language models (LMs) can learn about implicit syntactic relationship: that is, the filler-gap dependency. The filler-gap dependency refers to a relationship between a (wh-)filler, which is a wh-phrase like 'what' or 'who' overtly in clause-peripheral position, and its gap in clause-internal position, which is an invisible, empty syntactic position to be filled by the (wh-)filler for proper interpretation. Here to implement L2ers' English learning, we build LSTM LMs that in turn learn a subset of the known restrictions on the filler-gap dependency from English sentences in the L2 corpus that L2ers can potentially encounter in their English learning. Examining LSTM LMs' behaviors on controlled sentences designed with the filler-gap dependency, we show the characteristics of L2ers' sentence processing using the information-theoretic metric of surprisal that quantifies violations of the filler-gap dependency or wh-licensing interaction effects. Furthermore, comparing L2ers' LMs with native speakers' LM in light of processing the filler-gap dependency, we not only note that in their sentence processing both L2ers' LM and native speakers' LM can track abstract syntactic structures involved in the filler-gap dependency, but also show using linear mixed-effects regression models that there exist significant differences between them in processing such a dependency.

• Proceedings of the Korean Society for Information Management Conference
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• 1997.08a
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• pp.5-15
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• 1997

기존의 대부분의 정보 검색 시스템은 문서에 대한 ‘자동 색인 단계’를 거쳐 질의자의 요구에 적합한 문서들을 추출하도록 되어 있다. 이 과정에서 얼마나 적합한 문서를 빠짐없이 검색하였는가 하는 문제가, 검색 시스템의 효율성들 판단하는 데 가장 중요한 열쇠가 된다. 이 글에서는 ‘명사’ 중심의 키워드 추출이 안고 있는 몇 가지 문제점들에 관해서 논의하였다. 즉, 합성어 키워드 구축의 필요성, 동사 구문 정보에 대한 필요성, 부사구 표현에 대한 기술 필요성, 그리고 발화 상황이 고려되어야 하는 점등이 검토되었고, 이에 관한 해결책으로, 어휘정보 및 어절 정보, 나아가 구문 정보들을 담고 있는, 보다 체계적인 한국어 사전 시스템이 구축되어야 함을 강조하였다.

• Language and Information
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• v.17 no.2
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• pp.51-66
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• 2013

Korean is a wh-in-situ language where the wh-expression stays in situ with an obligatory Q-particle marking its interrogative scope. This paper briefly reviews some basic properties of the wh-question construction in Korean and shows how a typed feature structure grammar, HPSG (Pollard and Sag 1994, Sag et al. 2003), together with the notions of 'type hierarchy' and 'constructions', can provide a robust basis for parsing the wh-construction in the language. We show that this system induces robust syntactic structures as well as enriched semantic representations for real-time applications such as machine translation, which require deep processing of the phenomena concerned.

• Proceedings of the Korean Society for Language and Information Conference
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• 2002.02a
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• pp.195-204
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• 2002

The purpose of this paper is to analyze the lexical-semantic structure of morphologically derived passive verbs in Korean based on Pustejovsky (1995)'s Generative Lexicon Theory (GL) and to explain the change of the root verb's lexical-semantic structure by means of passivization. Passivization in this paper is defined as the unaccusaztivization. In Argument Structure of derived passive verbs, the agent argument is deleted and the theme argument is realized as a syntactic subject. As for Event Structure, derived passives express left-headed event (achievement), whereas their roots denote right-headed event (accomplishment). In Qualia Structure, passive verbs and root ones have the same Fomal Role, but in Agentive Role of passive verbs, an act weakens to a process. Both Formal and Agentive Roles have the same theme argument.