• The Journal of the Acoustical Society of Korea
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• v.36 no.5
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• pp.300-304
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• 2017

In a cylindrical sonar, a conventional broadband energy detector has limitations in the separation of adjacent targets. In this paper, a broadband detection algorithm using cross-correlation is applied to the cylindrical sonar to improve the bearing resolution. The proposed algorithm uses split beamforming before broadband detection processing using cross-correlation to generate half beams. The time delay obtained from the peak of correlation between half beams is used to estimate the bearing of target. Simulations demonstrate the improved performance of the proposed algorithm against the conventional algorithm.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.8
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• pp.1686-1692
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• 2012

Spreading sequence play an important role in wireless communications, such as in a CDMA(code division multiple access) communication system and multi-carrier spectrum communication system. Spreading sequences with low cross-correlation, in a direct-sequence spread spectrum communication system, help to minimize multiple access interference and to increase security degree of system. Analysis of cross-correlations between the sequences is a necessary process to design sequences. However it require lots of computing time for analysis of cross-correlations between sequences. In this paper we propose a method which is possible to compute effectively cross-correlation using subfield in the process of practical computation of cross-correlation between nonlinear binary sequences.

• The Journal of the Acoustical Society of Korea
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• v.21 no.3
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• pp.264-273
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• 2002

Adaptive filters cannot exactly estimate the echo path of the receiving room because of the cross-correlation of stereo signals. In this paper, a new pre-processing method reducing the cross-correlation without degradation of stereophony is proposed to enhance the performance of stereophonic acoustic echo canceller. To reduce the cross-correlation, absolutes of two orthogonal signals derived from each channel signals are added to original channel signals. Assuming that the power of each channel signal is larger than that of the cross-correlation, the computation of pre-processing can be reduced. As results of simulations, it is shown that the performance of stereo acoustic echo canceller with the proposed pre-processing method is better than that of conventional ones.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.6B
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• pp.746-751
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• 2001

일반적으로 음향 반향 제거기에서 적응필터의 안정성을 보장하기 위해서 동시통화 검출기(DTD)를 사용하여 원단화자 신호와 근단화자 신호의 존재 여부에 따라 적응필터 계수의 적응 여부를 결정한다. 본 논문에서는 두 개의 상호상관계수를 이용하여 계산량과 메모리 소자수 면에서 효율적인 동시통화 검출 알고리즘을 제안하였다. 제안된 알고리즘은 마이크로폰의 입력신호와 추정된 반향 신호간의 상호상관계수, 그리고 마이크로폰의 입력신호와 오차신호간의 상호상관계수를 이용하여, 주행 상황과 같이 심한 잡음 환경에서도 동시통화 구간의 시작점과 끝점 검출에 강인한 특성을 갖는다. 또한, 기존의 상호상관도를 이용하는 방법에 비하여 적은 양의 계산과 메모리를 필요로 하여 저가의 고정소수점 DSP를 이용한 실시간 구현에 적합하다. 성능 평가를 위하여 차내 핸즈프리 통신 환경에서 얻은 실측 데이터를 사용하여 기존의 방법과 비교하였다.

• The Korean Journal of Financial Studies
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• v.14 no.1
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• pp.83-96
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• 2008

본 연구는 Random Matrix Theory(RMT)방법에 의하여 분해된 상관행렬이 원래 주식간 상호작용을 충분히 반영하고 있는지 여부를 Mantegna(1999)에 의하여 제안된 주식 네트워크와 실증적으로 결합 검증하였다. 분석결과에 의하면, RMT 방법으로 분해된 상관행렬을 주식 네트워크와 결합하였을 때, 분해된 상관행렬은 주식간 상호작용에서 의미 있는 요인들의 속성을 적절히 반영하고 있다는 것을 실증적으로 확인할 수 있었다. 이러한 결과를 통하여, 주식간 상호작용을 계량화한 상관행렬을 RMT방법에 의하여 특정 속성을 갖는 상관행렬로 분해하여 재무이론과 결합 검증한다면, 주식간 상호작용을 보다 잘 이해하는데 유용한 방법이 될 수 있음을 확인하였다.

• The Journal of the Acoustical Society of Korea
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• v.14 no.2
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• pp.5-15
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• 1995

An application of the cross correlation technique by adopting ultrasonic waves for water pipe flow measuring purpose is studied. It is a non-intrusive flow metering method by determining the time of the flight of the flow turbulent noise and its non-obstructing mechanism enables to reduce process energy loss due to the flowmeter obstruction. A digital signal processor for the purpose of the real time Fourier transform was employed for the fast time calculation of the flow velocity. The overall accuracy was found as about $1\%$ for flow velocities from 0.25 m/s up to 16 m/s and for the pipe inside diameters from 50mm to 248mm. The cross correlation technique can be used for the tap water utility including most common liquid flows.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.1
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• pp.61-67
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• 2012

Spreading sequence is used for spreading spectrum in CDMA. For the purpose of minimizing multiple access interference and expanding linear span of the sequences, it is desirable to use such sequences with low correlation and high linear span. To obtain large family size and high linear span, the values of the correlation function of the sequences is more complex. In this paper, we propose the extended Zeng sequences with large family size and high linear span and analyze the correlation of the sequences.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.6
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• pp.2727-2734
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• 2013

This study was designed to examine the effect of maternal attachment of infant and parenting efficacy on infant-mother's interaction. The subject were 180 infant and their mother who were early childhood education service in G city. Data analysed with Pearson correlation, regression. The results were as follows. First, there were showed tendency of normal level that mother's attachment and parenting efficacy to infant, infant-mother's interactions. Second, there were significant positive relationships between the mother's attachment of infant and infant-mother's interactions. Third, there were significant positive relationships between the mother's parenting efficacy and infant-mother's interactions. Fourth, the mother's attachment of infant and parenting efficacy has effect on the infant-mother's interactions.

• Korean Journal of Childcare and Education
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• v.7 no.2
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• pp.97-113
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• 2011

This study was aimed to explore the relations between Father's language interaction and self-leadership, preschool adjustment of young children. The subjects consisted of 253 four- and five-years-old children and their father's. Data were analyzed by Pearson's r. The results of study were as follows; First, there were significant correlations between father's language and self-leadership of young children. Second, there were significant correlations between father's language and preschool adjustment of young children. The educational implications of these indicate that we need to actively develop programs to increase self-leadership and preschool adjustment of young children through parents education.

• The Journal of the Korea Contents Association
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• v.20 no.4
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• pp.475-486
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• 2020

This study aims to discover the mediating effect of Self-Encouragement and Self-Discouragement on the Relationships between Fear of Negative Evaluation and Social Interaction Anxiety. A questionnaire was conducted on 319 university students and the data was analyzed with Pearson's correlation and regression. As a result, there was a positive correlation between Fear of Negative Evaluation and Social Interaction Anxiety. Also, Fear of Negative Evaluation and Social Interaction Anxiety were positively correlated with Self-Discouragement and negatively correlated with Self-Encouragement. Next, multiple regression showed that Self-Discouragement has a perfect mediating effect and Self-Encouragement has a partial mediating effect on the Relationship between Fear of Negative Evaluation and Social Interaction Anxiety. These results imply that counselee with Social Interaction Anxiety can be treated effectively by promoting self-encouragement.