• Proceedings of The KACE
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• 2017.08a
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• pp.29-30
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• 2017

W-grammar(Van Wijngaarden grammar)[1].란 형식 문법의 한 종류인 문맥 자유 문법(Context-free grammar, CFG)의 대안으로, 두 개의 CFG가 서로 상호작용하면서 언어를 정의하도록 구성된 문법을 말하며 그 구성상의 특징을 감안하여 2-level grammar라고도 부른다. 현재 많은 프로그래밍 언어는 CFG를 기반으로 구성되어 있는데, 본 연구에서는 W-grammar로 교육용 프로그래밍 언어를 정의하여 CFG 기반이 아닌 W-grammar 프로그래밍 언어의 진입점을 제공함과 동시에 기저의 문법에 따른 계산가능성에 대해서 연구하는 토대를 쌓는 것을 목표로 한다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.4
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• pp.958-963
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• 2008

Korean language has different structural properties which are controlled by semantic constraints of verbs. Also, most of Korean sentences are complex sentences which consisted of main clause and embedded clause. Therefore it is difficult to describe appropriate syntactic grammar or constraint for the Korean language and the Korean parsing causes various syntactic ambiguities. In this paper, we suggest how to describe CFG-based grammar using sentence patterns as syntactic constraint and solve syntactic ambiguities. To solve this, we classified 44 sentence patterns including complex sentences which have subordinate clause in Korean sentences and used it to reduce syntactic ambiguity. However, it is difficult to solve every syntactic ambiguity using the information of sentence patterns. So, we used semantic markers with semantic constraint. Semantic markers can be used to solve ambiguity by auxiliary particle or comitative case particle.

• The Transactions of the Korea Information Processing Society
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• v.6 no.8
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• pp.2113-2123
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• 1999

The partial free order feature of Korean makes grammar size represented by CFG too big and that's why grammar has to contain all the ordered words. There are some problems to parse spoken language, because spontaneous spoken language has special features such as meaningless words, repetitious speech, etc. So, in this paper, we define 'Core-Concept' as the necessary element for parsing and we describe grammar only using Core-Concept. And we can prevent grammar from becoming very large and reduce an additional parsing burden as we select. Core-Concept described in grammar as parsing element. Through this strategy, we present that the simplified grammar can give us more efficient method to get right results. Experiments show that our parsing strategy has an average of 98% or over success rate in correct parsing results.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.5
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• pp.985-991
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• 2009

A grammar-based test case generation (GBTG) algorithm takes a grammar G and generates a subset of the language L(G) accepted by G, and called test cases for software product testing. As most languages specified with CFG are recursive, usually L(G) is so large that it is not practical to execute all the of the generated cases. Therefore, this paper presents some "tags" : extra-grammatical annotations which are designed to restrict the generation. A number of control mechanisms have been developed to prune the number of test cases generated while still producing a test set that covers the majority of inputs to the system.

• The KIPS Transactions:PartC
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• v.9C no.5
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• pp.699-708
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• 2002

Since various terminals and different networks get involved in playing of a multimedia presentation, the case that the presentation QoS at a destination should be different from the QoS of multimedia data at a source occurs frequently. For playing the multimedia presentation, the multimedia data at a source should be transcoded into the multimedia data satisfying the QoS required at the terminal. The problem of generating the transcoding path is that, for a given multimedia presentation, different transcoding paths depending the terminal and networks should be generated. That is, a fixed transcoding path cannot be applied to a multimedia presentation. Instead, whenever the terminal and network to play the presentation get determined, a proper transcoding path should be regenerated automatically. In this paper, the algorithm for generating the transcoding path and the method for checking the playability of the generated path are proposed. The generating algorithm adopted the technique of Context Free Grammar in describing the set of transcoding resources and a user's transcoding rules in order to utilize the well-known compiler techniques. For the playability check, a method of computing the transcoding time and the delay time between data units are proposed. Finally all the proposed methods were implemented in the stream engine, called Transcore and the presentation-authoring tool, called VIP, we had developed. And the test results with a sample scenario were presented at the last.