• 대한음성학회:학술대회논문집
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• 대한음성학회 2005년도 춘계 학술대회 발표논문집
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• pp.99-102
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• 2005

Research efforts have been made for out-of-vocabulary word rejection to improve the confidence of speech recognition systems. However, little attention has been paid to non-recognition sentence rejection. According to the appearance of pronunciation correction systems using speech recognition technology, it is needed to reject non-recognition sentences to provide users with more accurate and robust results. In this paper, we introduce standard phoneme based sentence rejection system with no need of special filler models. Instead we used word spotting ratio to determine whether input sentences would be accepted or rejected. Experimental results show that we can achieve comparable performance using only standard phoneme based recognition network in terms of the average of FRR and FAR.

• Membrane and Water Treatment
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• 제4권1호
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• pp.69-81
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• 2013

The pH-dependent inter-conversion of the three free chlorine species ($Cl_2$, HOCl, OCl-) present in the aqueous hypochlorite solution was theoretically investigated. Each species was found overwhelmingly present in a characteristic pH range. Hypochlorite treatment of the polyamide membrane was carried out over these pH ranges and various membrane responses were observed. As pH is less than 8, membrane tends to be N-chlorinated by $Cl_2$ and HOCl, and N-chlorinated membrane showed reduced water permeance and salt rejection. As pH rises to 10-12, $OCl^-$ appears to be the dominating chlorine species. Membrane hydrolysis was found to well interpret the improved water permeance and salt rejection. When the pH is between 8-10, both N-chlorination and hydrolysis contribute to the response of the membrane, and the treated membrane showed improved salt rejection but reduced water permeation. Excessive hydrolysis occurred while the membrane was treated at pH 13 for the much stronger alkalinity.

• 한국컴퓨터정보학회논문지
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• 제15권12호
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• pp.125-132
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• 2010

어휘 인식에서는 인식 학습 시 나타나지 않는 미 출현 트라이 폰이 존재하며, 이들 시스템에서는 모델 파라미터들의 초기 추정치를 생성하지 못하고 음소 데이터에 대한 모델을 구성할 수 없는 단점으로 인하여 가우시안 모델의 정확성을 확보하지 못하게 된다. 이를 개선하기 위하여 확률 분포를 이용한 모델 파라미터의 가우시안 모델 최적화 방법을 제안한다. 확률 분포의 가우시안 모델을 최적화하여 가우시안 모델의 정확성을 제공하고, 음소 단위로 데이터의 탐색을 지원하여 신뢰도가 향상되었다. 제안된 방법의 성능 평가를 위하여 실제 다양한 미등록어가 관측될 수 있는 대상으로 실험을 수행하였으며 본 연구에서 제안한 정규화 신뢰도를 이용한 미등록어 거절 알고리즘이 기존의 방법들에 비하여 평균 1.7%의 성능향상을 나타내었다.

• The Journal of the Acoustical Society of Korea
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• 제15권4E호
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• pp.14-20
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• 1996

The double mode SAW resonator filters have the serious shortcoming that out-of-band rejection above the passband is quite poor. Hence a new structure of the double mode filter is designed with the COM (Coupling Of MOdes) theory with better out-of-band rejection characteristics while keeping all the beauties of the conventional type. The second goal of the design is to reduce the planar size of the structure so that mass productivity of low frequency devices can be improved. For those purposes, several IDT's and relfector gratings are added to or subtracted from the conventional structure so that the modification can lead to better overall performance as a filter. As results of the investigation, several new double mode SAW resonator filter structures are developed. A new structure shows 10dB more out-of-band rejection that the conventional type with 25% reduced device size. Good agreement is demonstrated between the analytical results and experimental results for an illustrative 325MHz four pole resonator filter on 64°YX LiNbO3.

• 한국멀티미디어학회논문지
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• 제13권10호
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• pp.1436-1443
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• 2010

어휘 인식 시스템에서는 처리되는 어휘가 나타나지 않는 미 출현 트라이 폰이 존재하는 단점이 있으며 이에 따른 신뢰도의 분포를 가지고 있지 않기 때문에 정규화를 수행할 수 없다. 따라서 이를 개선하기 위하여 미등록어 거절 알고리즘에서 사용되는 어휘 관리를 최적화하고 음소 단위로 데이터 탐색을 지원하는 VCOR 시스템을 제안한다. 또한 VCOR에서는 어휘 정보를 효율적으로 제공하기 위해 확장 facet 분류를 이용하여 사용자에게 어휘 단위의 정보를 제공하고, 어휘에 대한 향상된 추적 관리 가능을 제공하여 어휘에 대한 인식의 정확성을 제공한다. 본 논문에서 제안한 시스템을 적용한 결과 시스템 성능에서 어휘 종속 인식률은 97.56%, 어휘 독립 인식률은 96.23%의 인식률을 나타내었다.

• 한국자동차공학회논문집
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• 제9권3호
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• pp.42-50
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• 2001

In this paper, the effects of scale formation in engine water jacket upon the thermal durability of engine itself and its component parts were studied. To understand the effect of quality of water, a full load engine endurance test for 50 hours was carried out with not-treated underground water. The followings were found through the tested engine inspection after the endurance test; 1-2 mm thick scale formation in the engine water jacket, valve seat wear, piston top land scuffing, piston pin stick, and cylinder bore scuffing in siamese area. In order to understand the causes of above test results, the heat rejection rate to coolant, the metal surface temperature of combustion chamber, and the oil and exhaust gas temperatures were measured and analyzed. The scale formed in the engine water jacket played a role as thermal insulator. The scale formed in the engine reduced the heat rejection rate to coolant and it caused to increase the metal surface temperature. The reduced heat rejection rate to coolant increased the heat rejection rate to oil and exhaust gas and increased the oil and exhaust gas temperature. Also, the reasons of valve seat wear, piston top land scuffing and cylinder bore scuffing, and piston pin stick quantitatively analyzed in this paper.

• 한국음향학회지
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• 제18권3호
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• pp.3-9
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• 1999

본 논문에서는 독립단어 음성인식 시스템을 위하여 반음소(anti-phone) 모델링을 이용한 인식 거절(rejection)기능에 대해 기술한다. 음성인식 거절 기능은 음성인식기를 제작할 ？ 정해놓은 인식대상 단어 이외의 단어가 입력되었을 때 그 단어가 인식할 수 없는 단어임을 알려주는 기능이다. 음성인식 거절기능을 구하는 방식은 핵심어 검출(keyword spotting)방식과 발화검증(utterance verification)방식으로 구분된다. 핵심어 검출 방식은 인식 대상 단어 외의 단어를 별도로 모델링하여 하나의 인식대상 단어처럼 사용하는 방식이고, 발화검증 방식은 각 음소마다 그와 유사한 anti-model을 작성한 후 정상적인 음소 모델과 anti-model과의 유사도를 비교하여 결정하는 방식이다. 본 연구에서는 독립단어 음성인식 시스템에 적용될 수 있는 발화 검증 방식에 의해 음성인식 거절 기능을 구현하였다. 특히 유사도를 결정함에 있어서 산술평균, 기하평균, 조화평균을 사용하고 각각을 비교하여, 기하평균을 사용하는 방식이 우수한 성능을 보임을 알 수 있었다. 음성의 신뢰도(confidence score)를 정규화하기 위해서 Sigmoid 함수를 사용하는데 이 함수의 가중치(weight) 상수의 변화에 대해 인식률을 비교함으로써 가장 적절한 가중치 상수값을 결정하였다. 그리고 유사음소집합(cohort set)에 대한 실험에서는 유사음소집합의 크기가 클수록 더 좋은 성능을 보이는 결과를 얻었다. 음성인식 테스트 결과에서는 신뢰도 임계치 값을 구하고 이 값을 사용하여 인식률을 계산하였으며, 거절의 오류까지 포함된 음성인식률은 약 76%였다. 이 연구결과는 현재 한국통신에서 시험 서비스 중인 음성인식 증권정보 안내 시스템에 적용될 예정이다.

• 한국생산제조학회지
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• 제9권1호
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• pp.60-67
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• 2000

An improved disturbance rejection control scheme is presented for minimizing the position error due to the repeatable runout disturbances in high density disk drive systems The proposed control algorithm is capable of attenuating repeatable disturbances which is one of the major detractors to hard disk drive quality and performance. This is achieved by a sys-tematic combination of an optimal feedback component and a feedforward preview component. The feedback component is designed where the emphasis is placed on robustness. The feedforward component is on the basis of a preview control comprised of a measured disturbance signals which leads to better disturbance rejection capabilites. The designed con-troller is applied as a plug-in module to a high density hard disk drive with a pre-existing conventional servo controller. Simulations have been carried out to demonstrate the effectiveness of this control scheme in the reduction of the periodic disturbances.

• 한국의류학회지
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• 제27권6호
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• pp.612-623
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• 2003

The purpose of this study was to find out the effects of mother's parenting attitudes on children's clothing orientation and clothing purchase behaviors. The questionnaires for this study were distributed to 166 fifth and sixth graders of elementary schools and 166 their mothers in Seoul. The data were analyzed through chi-square test, factor analysis, cluster analysis, MANOVA, ANOVA, and LSD test. Responses were classified as 4 groups (Acceptance-Autonomy, Acceptance-Control, Rejection-Autonomy, and Rejection- Control groups) based on mother's parenting attitude. The four groups showed significant differences both in clothing orientation and clothing purchase behaviors. Especially, the Rejection-Control group, which is easily influenced by peer students, placed much emphasis on fashionability of clothing and showed strong complaining behaviors toward unsatisfactory clothing selected by their mothers. Study results suggest the importance of mother's parenting attitude on analysis of target market for children's wear.

• ETRI Journal
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• 제34권4호
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• pp.518-526
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• 2012

This paper proposes LC voltage-controlled oscillator (VCO) phase-locked loop (PLL) and ring-VCO PLL topologies with low-phase noise. Differential control loops are used for the PLL locking through a symmetrical transformer-resonator or bilaterally controlled varactor pair. A differential compensation mechanism suppresses out-band spurious tones. The prototypes of the proposed PLL are implemented in a CMOS 65-nm or 45-nm process. The measured results of the LC-VCO PLL show operation frequencies of 3.5 GHz to 5.6 GHz, a phase noise of -118 dBc/Hz at a 1 MHz offset, and a spur rejection of 66 dBc, while dissipating 3.2 mA at a 1 V supply. The ring-VCO PLL shows a phase noise of -95 dBc/Hz at a 1 MHz offset, operation frequencies of 1.2 GHz to 2.04 GHz, and a spur rejection of 59 dBc, while dissipating 5.4 mA at a 1.1 V supply.