• 한국지능시스템학회논문지
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• 제21권4호
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• pp.463-468
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• 2011

지금까지 컨텍스트 예측 방법들은 이산 속성 컨텍스트를 대상으로 예측을 수행한 경우와 연속 속성 컨텍스트를 대상으로 예측을 수행한 경우로 나뉘어서 발전되어 왔다. 대부분의 예측 방법들은 컨텍스트의 획득 환경이나 특성에 맞게 특정 도메인에서 각각 예측 알고리즘을 작성하여 사용하여 왔기 때문에, 다양한 환경과 특성을 갖는 사용자의 컨텍스트를 대상으로 예측을 수행하기가 어렵다. 본 논문에서는 특정 도메인이나 컨텍스트의 특성에 국한되지 않고 이산 속성이나 연속 속성 컨텍스트들에 모두 적용 가능한 컨텍스트 예측 방법을 제안한다. 이를 위해 컨텍스트 속성간의 연관규칙을 고려하여 컨텍스트를 시퀀스로 생성하고, 컨텍스트 속성별 가변 가중치를 적용시켜 시퀀스 매칭 기반의 컨텍스트 예측을 수행한다. 제안한 방법을 평가하기 위해 이산 속성 컨텍스트와 연속 속성 컨텍스트에 각각 시뮬레이션한 결과 이산 속성 컨텍스트에서 80.12%, 연속 속성 컨텍스트에서 81.43%의 예측 정확도로 기존 예측방법들과 비슷한 성능을 보였다.

• 대한수학교육학회지:수학교육학연구
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• 제27권3호
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• pp.411-430
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• 2017

본 연구에서는 예비수학교사 24명을 대상으로 지수함수 맥락에서 지수함수의 그래프를 어떻게 구성하는지와 각 맥락의 교수학적 적절성에 대해서 어떻게 판단하는지를 살펴보았다. 제시된 지수함수 맥락은 무수히 많은 점을 이용하는 맥락과 무수히 많은 직선을 이용하는 맥락, 무한히 지급되는 이자 맥락이었다. 연구 결과, 예비교사들은 단계별로 그래프의 개형을 제시하는 과제에서 유한개의 점에 대한 그래프의 극한이라는 아이디어 A에서 가장 높은 이해도를 나타낸 반면에 한 점에서의 변화율과 함숫값이 비례한다는 아이디어 B와 연속 복리 개념이 내포된 아이디어 C를 사용한 그래프 구성에는 어려움을 나타내었다. 지수함수 그래프 구성 맥락이 적절한가에 대한 판단은 예비교사들의 내용교수지식에, 부적절하다는 판단은 수학의 내용지식 측면에 의존하는 경향이 나타났다. 예비교사들은 각 맥락에 따른 그래프를 구성하는 과정에서 나타나는 교수학적 조건과 상황을 언급하며 그래프 구성 맥락의 적절성을 주장한 반면에, 부적절성에 대해서는 각 맥락에 내포된 수학 개념의 본질과 논리적 관계들을 언급하였다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
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• pp.466-471
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• 2004

Efficient numerical finite element analysis of creeping concrete structures requires the use Kelvin or Maxwell chain model, which is most conveniently identified from a continuous retardation or relaxation spectrum, the spectrum in turn being determined from the given compliance or relaxation function. The method of doing that within the context of solidification theory for creep with aging was previously worked out by Bazant and Xi, but only for the case of a continuous retardation spectrum based on Kelvin chain. The present paper is motivated by the need to incorporate concrete creep into the recently published microplane model M4 for nonlinear triaxial behavior of concrete, including tensile fracturing and behavior under compression. In that context. the Maxwell chain is more effective than Kelvin chain. because of the kinematic constraint of the microplanes used in M4. Determination of the continuous relaxation spectrum for Maxwell chain. based on the solidification theory, is outlined and numerical examples are presented.

• Communications for Statistical Applications and Methods
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• 제6권1호
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• pp.207-220
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• 1999

In this paper, some of the issue about a group sequential method are considered in the Bayesian context. The continuous time optimal stopping boundary can be used to approximate the optimal stopping boundary for group sequential designs. The exact stopping boundary for group sequential design is obtained by using the backward induction method and is compared with the continuous optimal stopping boundary and the corrected continuous stopping boundary.

• 대한의용생체공학회:의공학회지
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• 제41권5호
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• pp.195-202
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• 2020

Needle detection in ultrasound images is sometimes difficult due to obstruction of fat tissues. Accurate needle detection using continuous ultrasound (CUS) images is a vital stage of treatment planning for tissue biopsy and brachytherapy. The main goal of the study is classified into two categories. First, new detection model, i.e. D-Attention Unet, is developed by combining the context information of 3D medical data and CUS images. Second, the D-Attention Unet model was compared with other models to verify its usefulness for needle detection in continuous ultrasound images. The continuous needle images taken with ultrasonic waves were converted into still images for dataset to evaluate the performance of the D-Attention Unet. The dataset was used for training and testing. Based on the results, the proposed D-Attention Unet model showed the better performance than other 3 models (Unet, D-Unet and Attention Unet), with Dice Similarity Coefficient (DSC), Recall and Precision at 71.9%, 70.6% and 73.7%, respectively. In conclusion, the D-Attention Unet model provides accurate needle detection for US-guided biopsy or brachytherapy, facilitating the clinical workflow. Especially, this kind of research is enthusiastically being performed on how to add image processing techniques to learning techniques. Thus, the proposed method is applied in this manner, it will be more effective technique than before.

• 한국음향학회지
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• 제22권5호
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• pp.388-402
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• 2003

In this paper, we carried out the word, 4 continuous digits. continuous, and task-independent word recognition experiments to verify the effectiveness of the re-defined phoneme-likely units (PLUs) for the phonetic decision tree based HM-Net (Hidden Markov Network) context-dependent (CD) acoustic modeling in Korean appropriately. In case of the 48 PLUs, the phonemes /ㅂ/, /ㄷ/, /ㄱ/ are separated by initial sound, medial vowel, final consonant, and the consonants /ㄹ/, /ㅈ/, /ㅎ/ are also separated by initial sound, final consonant according to the position of syllable, word, and sentence, respectively. In this paper. therefore, we re-define the 39 PLUs by unifying the one phoneme in the separated initial sound, medial vowel, and final consonant of the 48 PLUs to construct the CD acoustic models effectively. Through the experimental results using the re-defined 39 PLUs, in word recognition experiments with the context-independent (CI) acoustic models, the 48 PLUs has an average of 7.06%, higher recognition accuracy than the 39 PLUs used. But in the speaker-independent word recognition experiments with the CD acoustic models, the 39 PLUs has an average of 0.61% better recognition accuracy than the 48 PLUs used. In the 4 continuous digits recognition experiments with the liaison phenomena. the 39 PLUs has also an average of 6.55% higher recognition accuracy. And then, in continuous speech recognition experiments, the 39 PLUs has an average of 15.08% better recognition accuracy than the 48 PLUs used too. Finally, though the 48, 39 PLUs have the lower recognition accuracy, the 39 PLUs has an average of 1.17% higher recognition characteristic than the 48 PLUs used in the task-independent word recognition experiments according to the unknown contextual factor. Through the above experiments, we verified the effectiveness of the re-defined 39 PLUs compared to the 48PLUs to construct the CD acoustic models in this paper.

• 지식경영연구
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• 제12권2호
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• pp.56-68
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• 2011

The rapid changes in business environments are also applicable to the delivery service field. Numerous companies are using smart phones in order to perform work of the delivery service field that is rapidly developing every year. Smart phones established ubiquitous work environments where access to the server of the head office is possible through telephones, scanners, and the internet anywhere and anytime. However, although smart appliances including smart phones have been diffused, empirical analysis of use of them in actual has not been attempted much. In this regard, current study empirically analyzes how connectivity and context-awareness function of smart phones based on the TAM(Technology Acceptance Model) influence the continuous intention to use through trust, usefulness, and ease of use. The results indicate that the connectivity and context-awareness function, which are natures of smart phones, had impacts on the ease of use and trust, but not on the usefulness. Based on these results, this study suggests implications and future research directions regarding the planning and realization of smart appliances.

• 대한음성학회지:말소리
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• 제49호
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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.

• 한국음향학회지
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• 제22권3호
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• pp.175-181
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• 2003

한국어 숫자음은 단음절이며 연결된 숫자음 사이에 연음현상의 영향 때문에 한국어 연결 숫자음의 인식방법으로 반음절에 기반한 모델들이 제시되어 왔다. 기존에 제안된 반음절이나 반음절＋반음절의 인식모델을 이용한 방법에서는 아직까지 우수한 인식성능을 보이지 못하고 있다. 본 논문에서는 확장된 문맥종속 반음절 모델을 이용한 한국어 4 연숫자음 인식방법을 제안한다. 실험에서 연결숫자음은 SiTEC의 4 연숫자음 데이터 베이스를 사용하였으며 학습과 인식방법으로는 HTK 3.0의 C-HMM을 이용하였다. 기존의 방법들과 인식율을 비교해 본 결과, 92%의 비교적 우수한 인식성능을 보였다.

• 한국음향학회:학술대회논문집
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• 한국음향학회 1994년도 FIFTH WESTERN PACIFIC REGIONAL ACOUSTICS CONFERENCE SEOUL KOREA
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• pp.1027-1032
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• 1994

This paper introduces a interword modeling and a Viterbi search method for continuous speech recognition. We also describe a development of a real-time voice dialing system which can recognize around one hundred words and continuous digits in speaker independent mode. For continuous digit recognition, between-word units have been proposed to provide a more precise representation of word junctures. The best path in HMM is found by the Viterbi search algorithm, from which digit sequences are recognized. The simulation results show that a interword modeling using the context-dependent between-word units provide better recognition rates than a pause modeling using the context-independent pause unit. The voice dialing system is implemented on a DSP board with a telephone interface plugged in an IBM PC AT/486.