• The Journal of the Acoustical Society of Korea
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• v.22 no.1
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• pp.23-27
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• 2003

Recently attempts to we the syllable as the recognition unit to enhance performance in continuous speech recognition hate been reported. However, syllables are worse in their trainability than phones and the former have a disadvantage in that contort-dependent modeling is difficult across the syllable boundary since the number of models is much larger for syllables than for phones. In this paper, we propose a method to enhance the trainability for the syllables in Korean and phoneme-context dependent syllable modeling across the syllable boundary. An experiment in which the proposed method is applied to word recognition shows average 46.23% error reduction in comparison with the common syllable modeling. The right phone dependent syllable model showed 16.7% error reduction compared with a triphone model.

• Journal of the Korean Society for information Management
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• v.23 no.2
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• pp.147-165
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• 2006

The explosive growth of Web-based educational resources requires a new approach for accessing relevant information effectively. Social searching in the context of social navigation is one of several answers to this problem, in the domain of information retrieval. It provides users with not merely a traditional ranked list, but also with visual hints which can guide users to information provided by their colleagues. A personalized and context-dependent social searching system has been implemented on a platform called KnowledgeSea II, an open-corpus Web-based educational support system with multiple access methods. Validity tests were run on a variety of aspects and results have shown that this is an effective way to help users access relevant, essential information.

• Journal of Information Technology Services
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• v.12 no.3
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• pp.39-54
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• 2013

IT consulting is becoming a norm rather than exception in this age of smart work and information revolution. As IT consulting is one of the knowledge intensive services requiring high credence on both sides, maintaining a good trustful relationship is critical in sustenance of strategic partnership between business firms and IT service firms. Trust is known to be one of the salient constructs in service relationships. In this study, building from the social psychology literature, trust is conceptualized as two dimensions : cognitive and affective trust. Using two dimensions of trust as mediators, a research model is constructed for IT consulting specific context : relationship continuance intention as the dependent construct while expertise, service performance, reputation, relationship satisfaction and value similarity as antecedents of cognitive and affective trust. 145 data points were collected through a survey of IT service client project managers retrospectively asking their experience with IT consultants. Findings suggest that cognitive trust is associated with perceived level of expertise and service performance while affective trust with relationship satisfaction and value similarity, respectively. Interestingly, the paths from reputation are found to be statistically insignificant towards both dimensions of trust, indicating IT service context would be more practically outcome oriented than any other professional service context. Also, cognitive trust seems to maintain stronger influence on relationship continuance intention as anticipated. Implications and limitations are discussed at the end.

• The Journal of the Acoustical Society of Korea
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• v.18 no.8
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• pp.3-8
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• 1999

Previous variable vocabulary speech recognition systems with context-independent acoustic modeling, could not represent the effect of neighboring phonemes. To solve this problem, we use allophone-based context-dependent acoustic model. This paper describes the method to improve acoustic model of the system effectively. Acoustic model is improved by using allophone clustering technique that uses entropy as a similarity measure and the optimal allophone model is generated by changing the number of allophones. We evaluate performance of the improved system by using Phonetically Optimized Words(POW) DB and PC commands(PC) DB. As a result, the allophone model composed of six hundreds allophones improved the recognition rate by 13% from the original context independent model m POW test DB.

• International Journal of Computer Science & Network Security
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• v.22 no.3
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• pp.213-219
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• 2022

The main purpose of the study is to determine the main aspects of the introduction of modern management technologies into the security system in the context of socio-economic development and digitalization of the economy. Socio-economic development and a high level of security include growth in income, labor productivity, production volumes, increased competitiveness, changes in the institutional environment, consciousness, activity, social security, the quality of the education system, healthcare, etc. Despite the root cause of economic development, it is not an end in itself, but a tool for ensuring social development. Gaining access for citizens to education, health care, observance of the principles of equality and justice, ensuring protection are directly dependent on the level of economic well-being, the level of economic potential of the country or regions. The research methodology involved the use of both theoretical and practical methods. As a result of the study, the key elements of the introduction of modern management technologies into the security system in the context of socio-economic development and digitalization of the economy were identified.

• Structural Engineering and Mechanics
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• v.73 no.6
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• pp.725-735
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• 2020

The present investigation deals with the thermomechanical interactions in an orthotropic thermoelastic homogeneous body in the context of fractional order theory of thermoelasticity due to time harmonic sources. The application of a time harmonic concentrated and distributed sources has been considered to show the utility of the solution obtained. Assuming the disturbances to be harmonically time dependent, the expressions for displacement components, stress components and temperature change are derived in frequency domain. Numerical inversion technique has been used to determine the results in physical domain. The effect of frequency on various components has been depicted through graphs.

• Proceedings of the KSPS conference
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• 2002.11a
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• pp.197-200
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• 2002

In this paper, we propose a phoneme duration modeling in a speech recognition system based on disicion tree state tying. We assume that phone duration has a Gamma distribution. In a training mode, we model mean and variance of each state duration in context-independent phone model based on decision tree state tying. In a recognition mode, we get mean and variance of each context-dependent phone duration form state duration information obtaind during training mode. We make a comparative study of the proposed meth with conventinal methods. Our method results in good performance compared with conventional methods.

• MALSORI
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• no.49
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• pp.107-121
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• 2004

In this paper, we describe a cross-morpheme pronunciation variation model which is especially useful for constructing morpheme-based pronunciation lexicon to improve the performance of a Korean LVCSR. There are a lot of pronunciation variations occurring at morpheme boundaries in continuous speech. Since phonemic context together with morphological category and morpheme boundary information affect Korean pronunciation variations, we have distinguished phonological rules that can be applied to phonemes in within-morpheme and cross-morpheme. The results of 33K-morpheme Korean CSR experiments show that an absolute reduction of 1.45% in WER from the baseline performance of 18.42% WER was achieved by modeling proposed pronunciation variations with a possible multiple context-dependent pronunciation lexicon.

• Proceedings of the Acoustical Society of Korea Conference
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• 1998.06d
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• pp.60-63
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• 1998

본 논문에서는 사용자가 별도의 훈련과정 없이 인식대상 어휘를 추가 및 변경이 가능한 가변어휘 인식시스템에 관하여 기술한다. 가변어휘 음성인식에서는 미리 구성된 음소모델을 토대로 인식대상 어휘가 결정되명 발음사전에 의거하여 이들 어휘에 해당하는 음소모델을 연결함으로써 단어모델을 만든다. 사용된 음소모델은 현재 음소의 앞뒤의 음소 context를 고려한 문맥종속형(Context-Dependent)음소모델인 triphone을 사용하였고, 연속확률분포를 가지는 Hidden Markov Model(HMM)기반의 고립단어인식 시스템을 구현하였다. 비교를 위해 문맥 독립형 음소모델인 monophone으로 인식실험을 병행하였다. 개발된 시스템은 음성특징벡터로 MFCC(Mel Frequency Cepstrum Coefficient)를 사용하였으며, test 환경에서 나타나지 않은 unseen triphone 문제를 해결하기 위하여 state-tying 방법중 음성학적 지식에 기반을 둔 tree-based clustering 기법을 도입하였다. 음소모델 훈련에는 ETRI에서 구축한 POW (Phonetically Optimized Words) 음성 데이터베이스(DB)[1]를 사용하였고, 어휘독립인식실험에는 POW DB와 관련없는 22개의 부서명을 50명이 발음한 총 1.100개의 고립단어 부서 DB[2]를 사용하였다. 인식실험결과 문맥독립형 음소모델이 88.6%를 보인데 비해 문맥종속형 음소모델은 96.2%의 더 나은 성능을 보였다.

• Speech Sciences
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• v.10 no.1
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• pp.71-84
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• 2003

In the acoustic modeling for large vocabulary speech recognition, a sparse data problem caused by a huge number of context-dependent (CD) models usually leads the estimated models to being unreliable. In this paper, we develop a new clustering method based on the C45 decision-tree learning algorithm that effectively encapsulates the CD modeling. The proposed scheme essentially constructs a supervised decision rule and applies over the pre-clustered triphones using the C45 algorithm, which is known to effectively search through the attributes of the training instances and extract the attribute that best separates the given examples. In particular, the data driven method is used as a clustering algorithm while its result is used as the learning target of the C45 algorithm. This scheme has been shown to be effective particularly over the database of low unknown-context ratio in terms of recognition performance. For speaker-independent, task-independent continuous speech recognition task, the proposed method reduced the percent accuracy WER by 3.93% compared to the existing rule-based methods.