• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.7C
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• pp.459-466
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• 2011

This paper addresses the problem in the acquisition of binary offset carrier (BOC) signals employed in global navigation satellite systems, which is caused by the multiple side-peaks of the BOC autocorrelation function. We first observe that the side-peaks arise due to the fact that the BOC autocorrelation is made up of the sum of the sub-correlations shaped irregularly, and then, propose a novel acquisition scheme based on a recombination of the sub-correlations with cyclostationarity. The proposed scheme is demonstrated to remove the side-peaks completely for any type of BOC signal and to provide a performance improvement over the conventional schemes in terms of the mean acquisition time.

• The Korean Journal of Rehabilitation Nursing
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• v.5 no.2
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• pp.145-155
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• 2002

Purpose: This study tries to analyze the differences of memory performance and the metamemory of the elderly women according to degree of depression. And also it attempts to find the correlations among the sub-concepts of metamemory which have close relationships to the memory performance followed by the depression. Methods: The subjects of this study are 60 the elderly women who are older than sixty years in Busan city, Korea. We use the MIA(Dixon, et al., 1988) to measure metamemory and measure the memory performances such as the immeadiate word recall, the delayed word recall, the word recognition task, and face recognition. Results: 1. The average point of deprssed elderly womens' metamemory was significantly lower than non-depressed womens' point(t=10.86 p<.0017). Looking into subconcept of metamemory, depressed elderly womens' strategy, capacity, change, achievement point were significantly lower than non-depressed women. 2. In terms of immediate word recall and delayed word recall performances, depressed elderly women are significantly lower than non-depressed elderly women. 3. The degree of depressed elderly womens' metamemory(strategy, achievement, change, capacity) has significant correlations with immediate word recall performances. Conclusion: Metamemory has close relationship with the memory performance of elderly women. And also depressed elderly's sub-concepts of metamemory which have influences on their memory performance are different from non-depressed elderly's sub-concepts. Therefore, when we try to develop some programs to prevent memory decrease of elderly women, we should take these point into consideration.

• Journal of Engineering Education Research
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• v.26 no.2
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• pp.32-44
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• 2023

This research aims to examine the role of writing self-efficacy in engineering students' writing metacognitive strategies and writing apprehension. To achieve this purpose, first, the relationships among writing self-efficacy, writing metacognitive strategies and writing apprehension were investigated. Second, the effects of writing self-efficacy, as perceived by engineering students, on writing metacognitive strategies as well as writing apprehension were explored. A total of 173 engineering students from one university in Korea responded to survey based on a three-variables scale. The findings were that, firstly, positive correlations between writing self-efficacy and writing metacognitive strategies were identified in terms of sub-factors of those two variables. Secondly, negative correlations between writing apprehension and writing self-efficacy, and between writing apprehension and writing metacognitive strategies, were identified in terms of sub-factors of those variables. Thirdly, writing self-efficacy predicted engineering students' writing metacognitive strategies' sub-factors and writing apprehension. The practical implications of these findings are discussed herein, with particular attention on education for promotion of writing self-efficacy and reduction of writing apprehension.

• Korean Journal of Child Studies
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• v.1
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• pp.28-39
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• 1980

I. OBJECTIVES The aim of this study lies in examining following items: 1. Difference in creativity between boys and girls 2. Inter correlation of the sub-variables of creativity 3. Correlation between parent-child relationship and creativity 4. The relationship between creativity and number of siblings 5. Creativity and birth-order II. METHODS & PROCED URES 1. Instruments: Standardized Creativity Test and Parent-Child Relationship Test for children 2. Objects: 118 boys and 97 girls enrolled in primary schools in Seoul who were selected by random sampling 3. Procedure: (1) The data of the boy group and the girl group were analized by means of M,t, SD. (2)The relationships between creativity and the number of siblings as well as the relationship between creativity and birth order were analyzed by M. (3) Inter-correlations among the sub-factors of creativity were obtained in boys and girls. (4) Complex-correlations between creativity and parent child relationship were produced. III. RESULTS 1. There were no significant differences between boy and girl in creativity. 2. Inter correlation among the sub-factors of creativity Boy: The highest scores were obtained in fluidity, and adaptability, the lowest in originality and openness. Girl: The highest score were obtained in world scribbling and fluidity, the comparatively low were in originality and a match-problem. 3. Inter-correlation between creativity and parent-child relationship a. Father-son: The positive refusal type has the most significant relation and conflict type, discrepancy type, negative type in turn have significant inter-coorelations. b. Mother-son: Discrepancy type, conflict type, positive refusal type have high correlations, while negative refusal type, anticipation type, and anxiety show significance in 5% level. c. Father-daughter: Positive refusal type shows correlation of 5% level significance, while indulgence type shows negative correlation in 1% level significance. d. Mother-daughter: Discrepancy type shows 5% level significance, while indulgence type shows negative correlation in 1% level. 4. Concerning the number of siblings, it was found that, boys and girls alike, those grown among 3 or 5 showed most creativity. 5. Concerning the birth order, it was found that, boys and girls alike, the first child showed the most creativity, and the youngest showed the next to the most, while the middle showed the least creativity.

• Imaging Science in Dentistry
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• v.53 no.1
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• pp.77-82
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• 2023

Purpose: This study evaluated anatomical variations in the root canals of the lower premolars and molars in a Brazilian sub-population using cone-beam computed tomography (CBCT). Materials and Methods: In total, 121 CBCT images of patients were selected from a database. All images contained lower first and second premolars and molars on both sides of the arch, fully developed roots, and no treatment, resorption, or calcifications. In each image, the root canals of the lower premolars and molars were evaluated according to the Vertucci classification in On-Demand 3D software in the multiplanar reconstruction with dynamic navigation. Twenty-five percent of the images were re-assessed to analyze intraobserver confidence with the kappa test. Data were statistically evaluated with linear regression to evaluate the correlations of anatomic variations with age and sex, and the Wilcoxon test to analyze the laterality of variations, with a significance level of 5%. Results: The intraobserver agreement (0.94) was excellent. In general, the root canals of lower premolars and molars showed a higher prevalence of type I than other Vertucci classification types, followed by type V in premolars and type II in molars. When the molar roots were evaluated separately, type II was more frequent in mesial roots and type I in distal roots. Although age showed no correlations with the results, sex and laterality showed correlations with tooth 45 and the lower second premolars, respectively. Conclusion: The lower premolars and molars of a Brazilian sub-population showed a wide range of root canal anatomic variations.

• Progress in Superconductivity and Cryogenics
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• v.15 no.2
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• pp.16-19
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• 2013

The magneto-resistivity and electric field-current density (E-J) curves were investigated up to a magnetic field 9 T in the optimally doped $BaFe_{1.8}Co_{0.2}As_2$ single crystal with a superconducting temperature ($T_c$) of 24.6 K. The E-J Scaling behaviors below and above vortex glass transition temperature ($T_g$) were found, confirming the existence of the vortex glass phase transition. The critical exponents for the diverging spatial and time correlations at $T_g$, were obtained as v = $1.1{\pm}0.1$ and z = $4.5{\pm}0.3$, respectively. The obtained critical exponents are in good agreement with the predicted values of v ~ 1 - 2 and z > 4 within the 3D vortex glass theory.

• Journal of the Korean Wood Science and Technology
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• v.32 no.3
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• pp.8-14
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• 2004

Nondestructive evaluation (NDE) technique method using a resonance frequency mode was carried out for woodceramics produced at different carbonizing temperatures (600℃, 800℃, 1000℃, 1200℃, 1500℃) at the phenol resin impregnation rate of 70%, for three kinds of species (Pinus densifora, Pinus koraiensis, Larix leptolepis), respectively. There was a poor relationship between density and static bending MOR. However, close correlations were found between dynamic MOE_d and static bending MOR, and between static MOEs and MOR. Especially, the correlation coefficient was highest between MOE_d and static bending MOR. Therefore, the MOE_d using the resonance frequency mode is useful as a NDE method for predicting the MOR of woodceramics produced at different carbonizing temperatures.

• Korean Journal of Child Studies
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• v.19 no.2
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• pp.3-17
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• 1998

Five metropolitan cities in Korea were the setting for a survey of the use of media by 622 families. Correlations with children's problem behavior, cognitive development, and family environment were analyzed. Parents completed questionnaires on media use by family members, children's problem behavior, and family environment. Children were tested individually with 4 sub-scales of the Wechsler Intelligence Scale. There were age as well as sex differences in the use of media. There were correlations between children's use of media and their problem behavior, intelligence, and family environment. Regression analyses revealed that the parents' use of media was the most important determinant of children's use of media. Therefore, adult media education as well as children's education is recommended as a way to improve the media environment for children.

• The Korean Journal of Emergency Medical Services
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• v.17 no.1
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• pp.51-62
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• 2013

Purpose : The purpose of this study was to verify the effects of academic self-efficacy on self-directed learning attitude of emergency medical students. Methods : A total of 209 emergency medical technology students filled out the questionnaire after receiving the informed consents. The questionnaire consisted of demographical characteristics, academic self-efficacy and self-directed learning attitude. Results : Academic self-efficacy and self-directed learning attitude of the subjects were above mean average. Higher correlations existed between academic self-efficacy and self-directed learning attitude of the subjects, and the significant positive correlations were found between sub-factors of the academic self-efficacy and self-directed learning attitude. The academic self-efficacy of the subjects had the significant influence on the self-directed learning, and self-efficacy. The self-confidence among sub-factors in the academic self-efficacy had a significant influence on self-directed learning attitude and sub-factors. Conclusion : The results of the study subjects of academic self-efficacy had a significant influence on the attitude of self-directed learning, In particular, self-efficacy and confidence of the academic self-efficacy sub-factors showed a significant impact on the sub-factors, attitudes and self-directed learning. This study will provide the basic data for the implementation of the educational programs. This will be effective in managing the knowledge, information, self-directed learning attitude and academic self-efficacy.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.11C
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• pp.694-701
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• 2011

This paper addresses a synchronization technique based on an adaptive combining of the sub-correlation functions obtained from multiband sine phased binary offset carrier (BOC) signals, allowing a BOC signal receiver to deal with multiband sine phased BOC signals. Specifically, we first obtain the sub-correlation functions composing the BOC autocorrelation function, and then, re-combine the sub-correlation functions generating a correlation function with no side-peak. Finally, by replacing the BOC autocorrelation with the correlation function with no side-peak in the delay lock loop, the proposed scheme performs unambiguous signal tracking. The proposed synchronization scheme is applicable to generic sine phased BOC signals. Numerical results demonstrate that the proposed scheme provides a performance improvement over the conventional unambiguous schemes in terms of the tracking error standard deviation.