• Korean Journal of Cognitive Science
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• v.8 no.4
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• pp.1-10
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• 1997

The number of basic color names and the corresponding hues used in Korea were investigated. First, we did a field study about the color terms in Korean. Our results identify the color term inventory in Korean and permit a further test of Berlin and Kay's(1969) theory of color universals. Second, 36 subjets performed a color matching task. The matching task allows the referents and the best examplars of each color names to be determined. The hue area and the central hue corresponding to the basic color names were represented in the two dimensional color space. This study provides not only basic materials of Korean color term to psychology and linguistics but also bases for further study to the internal structure of Korean color categories.

• Journal of Fashion Business
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• v.14 no.5
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• pp.49-65
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• 2010

The purpose of this paper is to derive the categories of negative e-WOM (electronic word of mouth) via consumer review. Disclosing the details of negative e-WOM based consumer reviews has never been done before. For this reason, a content analysis was adopted to provide knowledge and understanding of the phenomenon. This paper analyzes the content of 630 consumer reviews posted on the open market internet site, www.auction.co.kr. The analysis was conducted from October 20th, 2008 to March 10th, 2009. The results indicated that the negative e-WOM based consumer reviews can be divided into two categories: the cognitive evaluation and the expression of consumer's emotion. The category of cognitive evaluation is consisted of negative e-WOM of product, negative e-WOM of service, and warning about the risk of purchasing products. The category of expressing consumers' emotion are composed of venting customers' dissatisfaction and passive response of dissatisfaction. Investigating the details of negative e-WOM has a number of implications. Most importantly, the results revealed multidimensional structure of negative e-WOM. This understanding of negative e-WOM communication allows marketers to improve products and services that better meet customers' current and future needs.

• Journal of The Korean Association For Science Education
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• v.22 no.5
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• pp.1030-1043
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• 2002

The development of cognitive psychology provides us a theoretical base from which we can obtain information about human problem solving. One purpose of this study was to investigate the effects of cognitive psychological factors on the problem solving of the two kinds of tasks (content free, content specific). And the other purpose was to find out the existence of critical situation in problem solving process. Even the items of tasks with the same logical structure and content knowledge could have different sizes of mental demand. The results were as follows. The mental demand of the problem, and the problem solver's mental capacity, might be the main factors in problem solving. Critical situation of both a group and an individual existed in the tasks that need content free knowledge (FIT 752 task). But the critical situation of a group was completely different from that of the individual in the tasks that need content specific knowledge (electric circuit task). According to the analysis of achievement for each individual in the task that need content specific knowledge, the critical situation of an individual existed in problem solving, but the critical situation of a group was not existed by were summed up the individual results.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.6C
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• pp.391-397
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• 2011

This paper investigates the frequency offset (PO) estimation scheme for the orthogonal frequency division multiplexing (OFDM)-based cognitive radio (CR) systems. In the CR environments, the conventional FO estimation schemes for the OFDM systems experience significant performance degradation due to the effect of the non-Gaussian noise. In this paper, a novel FO estimation scheme based on the maximum likelihood criterion is proposed for the OFDM-based CR systems in non-Gaussian noise environments. The proposed scheme does not require a specific pilot structure and has a better estimation performance compared with that of the conventional scheme.

• Annual Conference on Human and Language Technology
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• 2008.10a
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• pp.42-47
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• 2008

1980년대 중반부터 지난 20여 년간 구축해 온 영어 워드넷(PWN)은 인간의 심상어휘집을 재현하려는 목적으로 개발되기 시작하였으나, 그 활용 가능성에 주목한 것은 자연언어처리와 지식공학 분야다. 컴퓨터 매개 의사소통(CMC), 인간-컴퓨터 상호작용(HCI)에서 인간 언어를 자연스럽게 사용하여 필요한 정보를 획득하기 위해서는 의미와 지식의 처리가 필수적인데, 그 해결의 실마리를 어휘라는 실체를 가진 언어단위에서 찾을 수 있기 때문이다. 이후 전 세계적으로 약 50개 언어의 어휘의미망이 PWN을 참조모델로 구축되어 다국어처리의 기반을 제공할 뿐 아니라, 시맨틱 웹 이후 더욱 주목 받고 다양한 방식으로 활용되고 있다. 본고는 PWN을 참조 모델로 2004년부터 2007년까지 구축한 한국어 어휘의미망 KorLex 1.5를 소개하는 데 있다. 현재 KorLex은 명사, 동사, 형용사, 부사 및 분류사로 구성되며, 약 13만 개의 신셋과 약 15만 개의 어의를 포함하고 있다.

• ETRI Journal
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• v.37 no.6
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• pp.1077-1086
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• 2015

This paper presents a general-purpose design scheme of a filter bank (FB)-based radio frequency (RF) transceiver that operates across the entire ultra-high frequency (UHF) TV band from 470 MHz to 698 MHz and complies with the TV white space (TVWS) regulatory requirements. To this end, an intermediate frequency (IF) band-pass filter (BPF) with a sharp skirt characteristic is considered as a solution for handling the incoming signals from a baseband modem. Specifically, an FB-based BPF structure with four ceramic resonator filters that effectively rejects unwanted signals is proposed to extract a desired signal in the TV band. Achievable data rates of a cognitive radio system (CRS) employing the proposed FB-based RF transceiver at the application layer are investigated in both wired and wireless environments. The service coverage of the CRS network is measured according to several modulation and coding schemes (MCSs) of the CRS. The results show that the coverage of a wireless network in a nearly open area can be extended by more than 9.3 km in the TVWS. Experimental results also confirm that the proposed FB-based RF transceiver is adequate for utilization in TVWS applications.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.3
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• pp.211-217
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• 2011

This paper proposes a quasi-optimal linear DOA (Direction-of-Arrival) estimator which is necessary for the development of a real-time robot auditory system tracking moving acoustic source. It is well known that the use of conventional nonlinear filtering schemes may result in the severe performance degradation of DOA estimation and not be preferable for real-time implementation. These are mainly due to the inherent nonlinearity of the acoustic signal model used for DOA estimation. This motivates us to consider a new uncertain linear acoustic signal model based on the linear prediction relation of a noisy sinusoid. Using the suggested measurement model, it is shown that the resultant DOA estimation problem is cast into the NCRKF (Non-Conservative Robust Kalman Filtering) problem [12]. NCRKF-based DOA estimator provides reliable DOA estimates of a fast moving acoustic source in spite of using the noise-corrupted measurement matrix in the filter recursion and, as well, it is suitable for real-time implementation because of its linear recursive filter structure. The computational efficiency and DOA estimation performance of the proposed method are evaluated through the computer simulations.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.4
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• pp.38-42
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• 2008

In this paper, we propose a new structure for spectrum sensing which employs multiples energy detectors in multiple antenna system in order to improve its reliability. The performance is analyzed by simulation and compared to that of the conventional energy detector. The simulation results shows that the performance of the proposed scheme is much better than that of the conventional one. Additionally, the performance of is described in terms of ROC curve.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.11
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• pp.1132-1138
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• 2014

In this paper, we proposed three types of binomial filter for spectrum sensing in cognitive radio system. Three filters are binomial, negative binomial and composite binomial filters and the frequency responses of their transfer functions are analyzed and the numbers of stages to meet the required attenuation are driven. As a result of performance analysis in terms of the number of stages, negative and composite binomial filters are superior to the binomial filter. Since the proposed three filters have a unified cascaded structure and are easy to be implemented without any multiplier, it is expected that they will have wide applications.

• Communications for Statistical Applications and Methods
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• v.27 no.6
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• pp.603-624
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• 2020

There is an emerging interest in brain functional connectivity (FC) based on functional Magnetic Resonance Imaging in Alzheimer's disease (AD) studies. The complex and high-dimensional structure of FC makes it challenging to explore the association between altered connectivity and AD susceptibility. We develop a pipeline to refine FC as proper covariates in a penalized logistic regression model and classify normal and AD susceptible groups. Three different quantification methods are proposed for FC refinement. One of the methods is dimension reduction based on common component analysis (CCA), which is employed to address the limitations of the other methods. We applied the proposed pipeline to the Alzheimer's Disease Neuroimaging Initiative (ADNI) data and deduced pathogenic FC biomarkers associated with AD susceptibility. The refined FC biomarkers were related to brain regions for cognition, stimuli processing, and sensorimotor skills. We also demonstrated that a model using CCA performed better than others in terms of classification performance and goodness-of-fit.