• MALSORI
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• no.51
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• pp.151-165
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• 2004

For educational and research purposes, a Korean speech recognition platform is designed. It is based on an object-oriented architecture and can be easily modified so that researchers can readily evaluate the performance of a recognition algorithm of interest. This platform will save development time for many who are interested in speech recognition. The platform includes the following modules: Noise reduction, end-point detection, met-frequency cepstral coefficient (MFCC) and perceptually linear prediction (PLP)-based feature extraction, hidden Markov model (HMM)-based acoustic modeling, n-gram language modeling, n-best search, and Korean language processing. The decoder of the platform can handle both lexical search trees for large vocabulary speech recognition and finite-state networks for small-to-medium vocabulary speech recognition. It performs word-dependent n-best search algorithm with a bigram language model in the first forward search stage and then extracts a word lattice and restores each lattice path with a trigram language model in the second stage.

• MALSORI
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• no.59
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• pp.53-68
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• 2006

We report the evaluation results of the Korean speech recognition platform called ECHOS. The platform has an object-oriented and reusable architecture so that researchers can easily evaluate their own algorithms. The platform has all intrinsic modules to build a large vocabulary speech recognizer: Noise reduction, end-point detection, feature extraction, hidden Markov model (HMM)-based acoustic modeling, cross-word modeling, n-gram language modeling, n-best search, word graph generation, and Korean-specific language processing. The platform supports both lexical search trees and finite-state networks. It performs word-dependent n-best search with bigram in the forward search stage, and rescores the lattice with trigram in the backward stage. In an 8000-word continuous speech recognition task, the platform with a lexical tree increases 40% of word errors but decreases 50% of recognition time compared to the HTK platform with flat lexicon. ECHOS reduces 40% of recognition errors through incorporation of cross-word modeling. With the number of Gaussian mixtures increasing to 16, it yields word accuracy comparable to the previous lexical tree-based platform, Julius.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.7C
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• pp.538-543
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• 2012

The performance of the speech recognition engine is one of the most critical elements of the in-vehicle speech recognition interface. The objective of this paper is to develop an automated platform for running performance tests on the in-vehicle speech recognition engine. The developed platform comprise of main program, agent program, database management module, and statistical analysis module. A simulation environment for performance tests which mimics the real driving situations was constructed, and it was tested by applying pre-recorded driving noises and a speaker's voice as inputs. As a result, the validity of the results from the speech recognition tests was proved. The users will be able to perform the performance tests for the in-vehicle speech recognition engine effectively through the proposed platform.

• Proceedings of the KSPS conference
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• 2003.05a
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• pp.32-35
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• 2003

This paper describes our recent work for developing a baseline platform for Korean spoken dialog recognition. In our work, We have collected about 65 hour speech corpus with auditory transcriptions. Linguistic information on various levels such as mophology, syntax, semantics, and discourse is attached to the speech database by using automatic or semi-automatic tools for tagging linguistic information.

• The Journal of the Acoustical Society of Korea
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• v.24 no.8
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• pp.498-504
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• 2005

We introduce a Korean speech recognition platform (ECHOS) developed for education and research Purposes. ECHOS lowers the entry barrier to speech recognition research and can be used as a reference engine by providing elementary speech recognition modules. It has an easy simple object-oriented architecture, implemented in the C++ language with the standard template library. The input of the ECHOS is digital speech data sampled at 8 or 16 kHz. Its output is the 1-best recognition result. N-best recognition results, and a word graph. The recognition engine is composed of MFCC/PLP feature extraction, HMM-based acoustic modeling, n-gram language modeling, finite state network (FSN)- and lexical tree-based search algorithms. It can handle various tasks from isolated word recognition to large vocabulary continuous speech recognition. We compare the performance of ECHOS and hidden Markov model toolkit (HTK) for validation. In an FSN-based task. ECHOS shows similar word accuracy while the recognition time is doubled because of object-oriented implementation. For a 8000-word continuous speech recognition task, using the lexical tree search algorithm different from the algorithm used in HTK, it increases the word error rate by $40\%$ relatively but reduces the recognition time to half.

• Proceedings of the KSPS conference
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• 2005.11a
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• pp.215-218
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• 2005

This paper reports the current status of development of the Korean speech recognition platform (ECHOS). We implement new modules including ETSI feature extraction, backward search with trigram, and utterance verification. The ETSI feature extraction module is implemented by converting the public software to an object-oriented program. We show that trigram language modeling in the backward search pass reduces the word error rate from 23.5% to 22% on a large vocabulary continuous speech recognition task. We confirm the utterance verification module by examining word graphs with confidence score.

• KIISE Transactions on Computing Practices
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• v.21 no.6
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• pp.418-423
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• 2015

As the development of technology advances at exceptional speed, the functions of wearable devices become more diverse and complicated, and many users find some of the functions difficult to use. In this paper, the main aim is to provide the user with an interface that is more friendly and easier to use. The speech recognition is easy to use and also easy to insert an input order. However, speech recognition is problematic when using on a wearable device that has limited computing power and battery. The wearable device cannot predict when the user will give an order through speech recognition. This means that while speech recognition must always be activated, because of the battery issue, the time taken waiting for the user to give an order is impractical. In order to solve this problem, we use gesture recognition. This paper describes how to use both speech and gesture recognition as a multimodal interface to increase the user's comfort.

• Proceedings of the Korean Society of Computer Information Conference
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• 2020.07a
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• pp.129-130
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• 2020

본 논문에서는 청각장애인의 의사소통을 위한 안드로이드 애플리케이션 시스템 구현 결과를 보인다. 구글 클라우드 플랫폼(Google Cloud Platform)의 STT(Speech to Text) API를 이용하여 음성 인식을 통해 대화의 내용을 텍스트의 형태로 출력한다. 그리고 TTS(Text to Speech)를 이용한 음성 합성을 통해 텍스트를 음성으로 출력한다. 또한, 포그라운드 서비스(Service)에서 가속도계 센서(Accelerometer Sensor)를 이용하여 스마트폰을 2~3회 흔들었을 때 해당 애플리케이션을 실행할 수 있도록 하여 애플리케이션의 활용성을 높인 시스템을 개발하였다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2015.10a
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• pp.175-178
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• 2015

This paper presents a VR-simulated sailor training platform for emergency in order to prevent a human error that causes 60~80% of domestic/ abroad marine accidents. Through virtual reality technology, the proposed platform provides an interaction method for proficiency of procedures in emergency, and a crowd control method for controlling crowd agents in a virtual ship environment. The interaction method uses speech recognition and gesture recognition to enhance the immersiveness and efficiency of the training. The crowd control method provides natural simulations of crowd agents by applying a behavior model that reflects the social behavior model of human. To examine the efficiency of the proposed platform, a prototype whose virtual training scenario describes the outbreak of fire in a ship was implemented as a standalone system.

• Proceedings of the Korean Society of Computer Information Conference
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• 2017.01a
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• pp.43-44
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• 2017

본 논문에서는 상용화된 음성-인식 디바이스가 다른 임베디드 모듈과 통신하며 스마트홈 중앙처리 서버역할을 수행하려 할 때 제작사에 의해 개발되어지지 않거나 제한된 모듈과 서비스만을 제공한다는 문제점을 해결하기 위해 사용자가 직접 간단한 작업으로 원하는 기능의 모듈을 개발하여 자유롭게 음성인식명령을 추가할 수 있는 플랫폼을 제안한다. 본 논문에서 제안하는 플랫폼의 개념은 특정 OS에 종속되지 않으므로 다양한 시스템에서 제공될 수 있도록 설계되었으며 실험 플랫폼은 Windows기반으로 제작되었으나 다른 시스템에도 같은 개념을 적용하여 제작할 수 있다.