• The Journal of the Acoustical Society of Korea
• /
• v.28 no.2E
• /
• pp.43-50
• /
• 2009

To get more natural synthetic speech generated by a Korean TTS (Text-To-Speech) system, we have to know all the possible prosodic rules in Korean spoken language. We should find out these rules from linguistic, phonetic information or from real speech. In general, all of these rules should be integrated into a prosody-generation algorithm in a TTS system. But this algorithm cannot cover up all the possible prosodic rules in a language and it is not perfect, so the naturalness of synthesized speech cannot be as good as we expect. ANNs (Artificial Neural Networks) can be trained to learn the prosodic rules in Korean spoken language. To train and test ANNs, we need to prepare the prosodic patterns of all the phonemic segments in a prosodic corpus. A prosodic corpus will include meaningful sentences to represent all the possible prosodic rules. Sentences in the corpus were made by picking up a series of words from the list of PB (phonetically Balanced) isolated words. These sentences in the corpus were read by speakers, recorded, and collected as a speech database. By analyzing recorded real speech, we can extract prosodic pattern about each phoneme, and assign them as target and test patterns for ANNs. ANNs can learn the prosody from natural speech and generate prosodic patterns of the central phonemic segment in phoneme strings as output response of ANNs when phoneme strings of a sentence are given to ANNs as input stimuli.

• Proceedings of the CALSEC Conference
• /
• 2005.03a
• /
• pp.55-61
• /
• 2005

We will introduce a new web-based knowledge management system in progress, in which XML-based web information extraction and our structuring knowledge technologies are combined using ontology-based natural language processing. Our aim is to provide efficient access to heterogeneous information on the web, enabling users to use a wide range of textual and non textual resources, such as newspapers and databases, effortlessly to accelerate knowledge acquisition from such knowledge sources. In order to achieve the efficient knowledge management, we propose at first an XML-based Web information extraction which contains a sophisticated control language to extract data from Web pages. With using standard XML Technologies in the system, our approach can make extracting information easy because of a) detaching rules from processing, b) restricting target for processing, c) Interactive operations for developing extracting rules. Then we propose a structuring knowledge system which includes, 1) automatic term recognition, 2) domain oriented automatic term clustering, 3) similarity-based document retrieval, 4) real-time document clustering, and 5) visualization. The system supports integrating different types of databases (textual and non textual) and retrieving different types of information simultaneously. Through further explanation to the specification and the implementation technique of the system, we will demonstrate how the system can accelerate knowledge acquisition on the Web even for novice users of the field.

• English Language & Literature Teaching
• /
• v.18 no.2
• /
• pp.189-211
• /
• 2012

The purpose of the study was to explore ways to improve the test items on the Korean scholastic ability test. More specifically, the researchers investigated whether use of the target language in test items would make a difference in total scores, discriminatory power, and item difficulty. A total of 288 high school seniors participated in the study. The subjects were divided into the experimental group (N=145) and the control group (N=143). A 25-item test resembling the Korean scholastic ability test was administered to both groups. The experimental group was given items whose questions and alternatives were all presented in English, whereas the control group was given items whose questions and alternatives were presented in Korean only. Statistical analyses revealed that use of English vs. Korean in the questions and alternatives made a significant difference in total scores, item discrimination, and item difficulty level. The findings strongly suggest that use of English is one way to improve the quality of the Korean scholastic ability test by enhancing item discrimination and face validity. Considering that the test in question is a high-stakes exam in Korea, further research on how to improve the Korean scholastic ability test is urgently called for.

• Phonetics and Speech Sciences
• /
• v.3 no.3
• /
• pp.77-88
• /
• 2011

Foreign accent in second language production depends heavily on the transfer of features from the first language. This study examines acoustic variations in segments and suprasegments by native and nonnative speakers of English, searching for patterns of the transfer and plausible indexes of foreign accent in English. The acoustic variations are analyzed with recorded read speech by 20 native English speakers and 50 Korean learners of English, in terms of vowel formants, vowel duration, and syllabic variation induced by stress. The results show that the acoustic measurements of vowel formants and vowel and syllable durations display difference between native speakers and nonnative speakers. The difference is robust in the production of lax vowels, diphthongs, and stressed syllables, namely the English-specific features. L1 transfer on L2 specification is found both at the segmental levels and at the suprasegmental levels. The transfer levels measured as groups and individuals further show a continuum of divergence from the native-like target. Overall, the eldest group, students who are in the graduate schools, shows more native-like patterns, suggesting weaker foreign accent in English, whereas the high school students tend to involve larger deviation from the native speakers' patterns. Individual results show interdependence between segmental transfer and prosodic transfer, and correlation with self-reported proficiency levels. Additionally, experience factors in English such as length of English study and length of residence in English speaking countries are further discussed as factors to explain the acoustic variation.

• Phonetics and Speech Sciences
• /
• v.13 no.1
• /
• pp.25-36
• /
• 2021

This study examined the perception and production of eight English fricatives /f/, /v/, /θ/, /ð/, /s/, /z/, /ʃ/, and /ʒ/ by thirty Chinese English majors and thirty Chinese middle school students through a fricative identification test, an intelligibility test, and a goodness rating test and focused on error patterns and the perception-production relationship. The results showed that substitution errors occurred frequently in the perception and production of English fricatives by both the English majors and the middle school students. Further, the error patterns were attributed to various influencing factors such as the negative transfer from Chinese consonant inventory, hypercorrection or overcompensation mistakes, deficiency of L2 teaching, and acoustic similarities. Significant overall correlations were found between the fricative perception and production by the two subject groups but were not manifested in all the eight fricatives, indicating that Chinese learners' perceptual competence of target fricatives was not necessarily tied to their productive excellence of those sounds in all cases. Furthermore, precedences of perception over production were incompletely manifested in the eight fricatives, which suggested that perception might not always be a necessary prerequisite for production. Additionally, subject group and vowel context differences were observed. The English majors performed better than the middle school students, both perceptually and productively, and the subjects' performances in perception and production varied when vowel contexts changed.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.15 no.11
• /
• pp.4184-4202
• /
• 2021

Text steganography combined with natural language generation has become increasingly popular. The existing methods usually embed secret information in the generated word by controlling the sampling in the process of text generation. A candidate pool will be constructed by greedy strategy, and only the words with high probability will be encoded, which damages the statistical law of the texts and seriously affects the security of steganography. In order to reduce the influence of the candidate pool on the statistical imperceptibility of steganography, we propose a steganography method based on a new sampling strategy. Instead of just consisting of words with high probability, we select words with relatively small difference from the actual sample of the language model to build a candidate pool, thus keeping consistency with the probability distribution of the language model. What's more, we encode the candidate words according to their probability similarity with the target word, which can further maintain the probability distribution. Experimental results show that the proposed method can outperform the state-of-the-art steganographic methods in terms of security performance.

• ETRI Journal
• /
• v.45 no.1
• /
• pp.18-27
• /
• 2023

We present an English-Korean speech translation corpus, named EnKoST-C. End-to-end model training for speech translation tasks often suffers from a lack of parallel data, such as speech data in the source language and equivalent text data in the target language. Most available public speech translation corpora were developed for European languages, and there is currently no public corpus for English-Korean end-to-end speech translation. Thus, we created an EnKoST-C centered on TED Talks. In this process, we enhance the sentence alignment approach using the subtitle time information and bilingual sentence embedding information. As a result, we built a 559-h English-Korean speech translation corpus. The proposed sentence alignment approach showed excellent performance of 0.96 f-measure score. We also show the baseline performance of an English-Korean speech translation model trained with EnKoST-C. The EnKoST-C is freely available on a Korean government open data hub site.

• Asia Pacific Journal of Corpus Research
• /
• v.4 no.1
• /
• pp.61-71
• /
• 2023

This study examines the effects of data-driven learning (DDL)-an approach employing corpora for inductive language pattern learning-on error identification in second language (L2) writing. The data consists of error identification instances from fifty-five participants, compared across different reference materials: the Corpus of Contemporary American English (COCA), dictionaries, and no use of reference materials. There are three significant findings. First, the use of COCA effectively identified collocational and form-related errors due to inductive inference drawn from multiple example sentences. Secondly, dictionaries were beneficial for identifying lexical errors, where providing meaning information was helpful. Finally, the participants often employed a strategic approach, identifying many simple errors without reference materials. However, while maximizing error identification, this strategy also led to mislabeling correct expressions as errors. The author has concluded that the strategic selection of reference materials can significantly enhance the effectiveness of error identification in L2 writing. The use of a corpus offers advantages such as easy access to target phrases and frequency information-features especially useful given that most errors were collocational and form-related. The findings suggest that teachers should guide learners to effectively use appropriate reference materials to identify errors based on error types.

• Journal of the Korean Institute of Telematics and Electronics B
• /
• v.31B no.11
• /
• pp.36-44
• /
• 1994

In this paper, a high-level process control language is developed to construct multi-loop controllers for large scale process control systems. Function locks are defined which are basic functions necessary to configure a multi-loop controller. Each block is presented to the function code which is a line of ASCII codes and has the characteristics to be simple and to be easily understood. A control algorithm for a process is attained by means of the arrangement of function codes with order. In order to be used to various environments of target hardwares, a transformation program is prepared that transfers a control program configured by function codes to a C-language program. The proposed control language is easy and simple to use, possible to expend, and able to apply to various control systems. Simulation results are included to show the availability for the usage of the proposed control language in real world.

• Journal of Internet Computing and Services
• /
• v.11 no.4
• /
• pp.107-117
• /
• 2010

The feature models representing the common and variable concepts among the software products and the feature configurations generated by selecting the features to be included in the target product are the essential components in the software product lines methodology. Although the researches on the formal semantics and reasoning of the feature models and feature configurations are in progress, the researches on feature model ontologies and feature configuration validation using the semantic web technologies are yet insufficient. This paper defines the formal semantics of the feature models and proposes a feature configuration validation technique based on ontology and semantic web technologies. OWL(Web Ontology Language), a semantic web standard language, is used to represent the knowledge in the feature models and the feature configurations. SWRL(Semantic Web Rule Language), a semantic web rule languages, is used to define the rules to validate the feature configurations. The approach in this paper provides the formal semantic of the feature models, automates the validation of feature configurations, and enables the application of various semantic web technologies, such as SQWRL.