• Korean Journal of Cognitive Science
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• v.25 no.2
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• pp.91-107
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• 2014

The syllable frequency effect is defined as the inhibitory effect that words starting with high frequency syllable generate a longer lexical decision latency and a larger error rate than words starting with low frequency syllable do. Researchers agree that the reason of the inhibitory effect is the interference from syllable neighbors sharing a target's first syllable at the lexical level and the degree of the interference effect correlates with the number of syllable neighbors or stronger syllable neighbors which have a higher word frequency. However, although the syllable frequency can be classified as the syllable type and token frequency, previous studies in visual word recognition have used the syllable frequency without the classification. Recently Conrad, Carreiras, & Jacobs (2008) demonstrated that the syllable type frequency might reflect a sub-lexical processing level including matching from letters to syllables and the syllable token frequency might reflect competitions between a target and higher frequency words of syllable neighbors in the whole word lexical processing level. Therefore, the present study investigated their proposals using word naming tasks. Generally word naming tasks are more sensitive to sub-lexical processing. Thus, the present study expected a facilitative effect of high syllable type frequency and a null effect of high syllable token frequency. In Experiment 1, words starting with high syllable type frequency generated a faster naming latency than words starting with low syllable type frequency with holding syllable token frequency of them. In Experiment 2, high syllable token frequency also created a shorter naming time than low syllable token frequency with holding their syllable type frequency. For that reason, we rejected the propose of Conrad et al. and suggested that both type and token syllable frequency could relate to the sub-lexical processing.

• Journal of Satellite, Information and Communications
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• v.11 no.3
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• pp.119-122
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• 2016

Feature detection is recognized as an accurate spectrum sensing approach when the information of the desired signal is partly known at the receiver. This type of detection was proposed to overcome large noise environment. Cyclostationary detection is an example of feature detection in spectrum sensing technique in cognitive radio. However, the cyclostationary process calculation requires a lot of processing time and information about the designed signals. On the other hand, energy detection spectrum sensing is widely known as a simple and compact spectrum sensing technique. However, energy detection is highly affected by large noise and lead to high detection error probability. In this paper, the combination of energy detection and cyclostationary is proposed in order to increase the accuracy and decrease the calculation and processing time. The two-layer threshold is utilized in order to reduce the complexity of computation and processing time in cyclostationary which can lead to the improved throughput of the system. The simulation result shows that the implementation of energy-based cyclostationary detector can help to improve the performance of the system while it can considerably reduce the required time for signal detection.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.18 no.2
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• pp.145-153
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• 2007

Objectives: This study was focused on the influence of chronic aircraft noise exposure on children's continuous performance, intelligence and reading skill. Methods: We enrolled 586 children in 4-6th grade of 7 primary schools near air base in Korea. Continuous performance was measured using the computerized ADS program. We analyzed 477-512 children on the visual continuous performance test, auditory continuous performance test, intelligence test, and reading and the vocabulary test. Intelligence was measured using vocabulary, digit span, block design, and digit symbol tests of K-WISC-III. Results: The commission error and variability deviation of auditory continuous performance test and reading test were significantly higher among children in schools with the helicopter noise and the fighting plane noise compared to children in the low noised schools. Conclusion: There was a possibility that chronic aircraft noise exposure was associated with impairment of the school performance. The result of our study also shows chronic aircraft noise was associated with reading ability.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.6
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• pp.101-108
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• 2013

In this paper, we propose a method in which the negative acknowledge (NACK) message is used as command for cooperation and spectrum sharing. This allows for an automatic request for cooperation and sharing when the direct link of the primary user is in outage, and also allows for saving the number of control messages in cooperation-spectrum sharing based paradigm. In the sharing phase, the selected relay shares a power fraction of $1-{\alpha}$ for secondary transmitted signal while the remaining of ${\alpha}$ is for primary retransmitted signal. In the case of no relay collected, primary transmitter uses NACK as a command to retransmit the signal with fully power fraction (${\alpha}=1$). Both systems are assumed to employ BPSK signals. In this scheme, we propose the joint optimal decoding in the secondary user. The frame error rate (FER) performance at both systems is then analyzed. The theoretical and simulation results validate the analysis and confirm the efficiency of the protocol.

• Korean Journal of Child Studies
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• v.6 no.1
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• pp.17-40
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• 1985

This study investigated Korean children's early acquisition of negatives and focused on four research questions: 1) processing of negative variations; 2) the nature of negatives when negatives are completely acquired in Korean (in which meaning and form are matched in one to one mapping); 3) the validity of Bellugi's negative acquisition model in Korean; and 4) the cause of child's erroneous sentence production: limited ability or regularity in children's cognition. The language data of the five subjects (age span; 1.1 - 3.11) were collected by their parents in the natural setting of the home. The results showed that 1) the pivot form, was processed in many ways from a simple to a complicated form, such as <(X+X')+N> <(x+x')+N,Y> <(x+x') N,(y+y')>. It appeared that the children used a simple negative format to reach a one-step advanced negative format. 2) Korean negatives are divided into range of negation in the negative sentence (part or whole), strength of negation (absolute or general), functions of meaning (negation, absences, refusal, prohibition, impossibility). All five children acquired negative sentences in all functions and the complete range after 3 years of age. 3) In spite of the differences in age level, Bellugi's four stage model was in evidence; that is, Korean children's negative acquisition was almost identical with Bellugi's tour stage model in deep structure. 4) Analyses of children's error sentences showed that the sentences with errors were made not because of the children's limitation in cognitive ability but because of the strict application of regularity of rules from the original grammars. Consequently, the children produced negative sentences using two rules: the rule of additive complexity (from simple to complex) and the rule of division (from one to several).

• Journal of Korean Society of Forest Science
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• v.99 no.6
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• pp.891-899
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• 2010

The purpose of this study is to estimate economic value of forest landscape function using conditional logit model, applied by Choice Experiment. For the study, we have chosen attributes and levels of forest landscape. In specific, topographical forest type, forest type, forest density, recreational factor (side trip, accessibility of valley) and WTP were included in attributes. Based on factors, we have made 48 choice sets with Balanced and Orthogonal form using SAS 9.1. The efficiency of questionnaire was 6.02 (D-Error: 0.1) and choice set and socio-economic variable were selected. In order to reduce cognitive load of respondent, 96 choice sets were divided into 4 types in questionnaire so that respondent could respond to 12 choice sets respectively. Population was citizens from 7 metropolitan cities including Seoul, and the interview survey was conducted to find out average annual WTP per household for the total 280 interviewees. As a result, In the Non-ASC model, Mcfadden' ${\rho}$ had 0.21, and Log Likelihood: -2,631. Average annual WTP per household for forest landscape was 266,723 Won(Korean currency).

• Journal of Sensor Science and Technology
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• v.12 no.6
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• pp.289-297
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• 2003

In this paper, we propose accurate classification method of an EEG signals during a mental tasks. In the experimental task, subjects achieved through the process of responding to visual stimulus, understanding the given problem, controlling hand motions, and select a key. To recognize the subjects' selection time, we analyzed with 4 types feature from the filtered brain waves at frequency bands of $\alpha$, $\beta$, $\theta$, $\gamma$ waves. From the analysed features, we construct specific rules for each subject meta rules including common factors in all subjects. In this system, the architecture of the neural network is a three layered feedforward networks with one hidden layer which implements the error back propagation learning algorithm. Applying the algorithms to 4 subjects show 87% classification success rates. In this paper, the proposed detection method can be a basic technology for brain-computer-interface by combining with discrimination methods.

• Communications of Mathematical Education
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• v.21 no.3
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• pp.407-430
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• 2007

The extreme didactic phenomena that occur by ignoring or overemphasizing the process of personalization/contextualization, depersonalization/decontextualization of mathematical knowledge is always in our teaching practice and in fact, seems to be a kind of phenomena that suppress teachers psychologically or didactically. The study of the problems on error, misconception or obstacles revealed by students has been done continuously, but that of the extreme didactic phenomena revealed by teachers has not. In this study, I will explain four extreme didactic phenomena and help you understand them by giving various examples from several case studies and analyzing them. And also, I will discuss the way to overcome the extreme didactic phenomena in the mathematical class, based on this analysis. This thesis will become a standard of didactic phenomena that are proceeded extremely by having teachers reconsider their own classes and furthemore, will offer the research data for considering better didactic situation.

• Journal of The Korean Association For Science Education
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• v.33 no.5
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• pp.881-892
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• 2013

It has been recently emphasized that comprehensive understanding of students' cognitive activities in the process of writing as well as final product is needed in order to develop an effective strategy for science writing. In this study, we investigated the characteristics of writing process in the situation that students wrote a composition in solving the application problem on a science topic. Seven eighth graders selected in the consideration of their science achievement and communication skills were asked to write a composition using think-aloud method. They were also interviewed after their writing work. The analyses of the results indicated that students' writing processes consisted of six distinctive components: generating, organizing, setting, translating, evaluating, and revising. It was also found that the patterns of process components for each student were different in terms of the frequency and the sequence. The patterns of process components were categorized into four types: systematic, tacit planning, trial and error, and random strategies. Educational implications were also discussed.

• Journal of the Korea Convergence Society
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• v.11 no.3
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• pp.187-194
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• 2020

This paper is a study to improve the usability due to the commercialization of open source-based knitting machines. Based on the analysis, FGD was conducted to derive considerations and to evaluate the evaluation factors based on the derived contents. Based on the evaluation principles derived, tasks were created for each UI (user interface) situation to measure execution time and error frequency. The analysis results show that model C has the highest user-friendliness in terms of learning, conciseness, cognitive fitness, convenience, state maintainability, and intuition. Ease of use will be improved.