• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• 제19권3호
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• pp.156-161
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• 2008

Objectives: The purpose of this study was to investigate the prevalence of sleep problems in Korean elementary school children and the differences in sleep problems elated to their school grade and gender. Methods : One public elementary school in Dae-gu, Korea as randomly selected. And, parents who agreed to participate this study were asked to complete a modified version of Tucson Children's Assessment of Sleep Apnea screening questionnaire (TuCASA). Results: The most common sleep problem was 'falling asleep in vehicle (44.2%)' and the prevalence rate of this problem differed by school grade. The prevalence rate of falling asleep while watching TV before 8 P.M. (8.0%), daytime fatigue (21.9%) and nocturnal enuresis during the past 6 months (5.3%) were significantly differed by school grade. The prevalence rate of falling asleep while doing home work, falling sleep during a lesson, snoring and bruxism were 12.6%, 1.0%, 26.7% and 13.2% respectively. Although these rates did not show any differences between grades, snoring as more in boys and daytime fatigue was more in girls. Conclusion: This study demonstrates that many elementary school children may have various sleep problems. Lower grade elementary schoolers had sleep problems which related to euro-developmental factors, whereas higher grade elementary schoolers had sleep problems related to sleep deprivation and stress. Finally, more female schooler showed signs of fatigue or sleepiness than male schoolers.

• 치위생과학회지
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• 제20권4호
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• pp.252-260
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• 2020

Background: In this study, the bleaching effect and surface damage of two types of over-the-counter home tooth bleaching agents were explored using an in vitro study of bleaching agents applied to bovine teeth specimens for 14 days. Methods: Domestic over-the-counter home tooth bleaching agents of gel and patch form that shared common active ingredients and manufacturers were selected and tested. The experiment specimens were made using composite resin with bovine tooth samples and then measured the initial microhardness. Specimens were then divided into a Gel group and a Patch group and underwent bleaching treatment once a day for two weeks for 30 to 60 minutes (recommended) or 7 hours. All specimens were coffee-stained prior to bleaching. The bleaching effect was measured using a spectrophotometer and surface damage was measured using a microhardness meter. Results: The difference in color following the bleaching procedure was positive in both the Gel and Patch group, although there were no statistically significant differences in bleaching effect between groups. There was no significant difference in bleaching effect based on duration. The microhardness test revealed that both the Gel group and the Patch group had surface damage after bleaching. The greatest surface damage was found in the Patch group that had undergone a 7-hour bleaching treatment, although the differences were not statistically significant. Conclusion: The bleaching effect of the home tooth bleaching agent was visible to the naked eye. However, longer applications than recommended did not result in greater bleaching, unlike consumers' expectations, and instead increased the chance of enamel damage. As such, there is a need for consumers to be alert and adhere to recommendations provided by each company.

• 한국대기환경학회지
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• 제20권1호
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• pp.111-118
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• 2004

In order to compare the NVOC (Natural Volatile Organic Compound) emission rates from oak trees, the emission rates of isoprene were quantitatively measured in situ based on tree species and region. As a result, the emission rates from Quercus serrata T. were found to be 1000 times greate. than those from Quercus acutissima C. However, the emission rates at the Chili and Gumsung mountain sites did not show any significant differences in summer. Cuvette tests using four different oak species also supported that there was a tremendous difference in emission rates between Quercus serrata T. and Quercus acutissima C. It was found that the emission rates from the trees were highest on the order of Quercus serrata T., Quercus aliena B., Quercus acutissima C. and Quercus variabilis B.

• 음성과학
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• 제8권2호
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• pp.7-22
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• 2001

This research with 40 hearing impaired children was performed to find out the characteristics of the phonological processes for each age, hearing loss degree and aided threshold degree through the transcriptions. The phonological processes of hearing impaired children are similar to those of normal children with a peculiar type of patterns in phonological processes. The results show that: (1) Between 5 and 6 year old groups the phonological processes were significantly different in palatal backing, glottal replacement and frication; between 6 and 7 year old groups the phonological processes were significantly different in velar fronting, labialization, alveolization and labial assimilation; between 7 and 8 year old groups the phonological processes, labialization, alveolization and alveolar assimilation, however 8 year old group showed more phonological processes than 7 year old group. (2) Between moderately-severe and severe hearing impaired groups, phonological processes were significantly different in the omissions of postvocalic, nasal and velar, stopping and stop assimilation. The differences of severe and profound groups were not found at all. (3) Aided hearing thresholds did not show any significant difference.

• 생물정신의학
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• 제25권3호
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• pp.53-59
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• 2018

Objectives The purpose of this study is to investigate the differences between a attention deficit hyperactivity disorder (ADHD) group and a general student group in terms of the perception of the residential environment and periodic activities outside the classroom. Methods The patient group consisted of 62 outpatients or inpatients at the Department of Pediatric Psychiatry, and 49 patients diagnosed with ADHD were selected. For the control group, 3727 youths in elementary schools, middle schools, and high schools of one city were asked to fill out questionnaires. Of the 1717 respondents who responded to the questionnaires, 245 were selected for a patient-controlled study. The differences between the patient group and the control group were compared using the chi-squared test (${\chi}^2$ test). Results There was a significant difference between the patient group and the control group in areas where students responded by "My neighborhood is dirty and littered (p < 0.05)". There was also a significant difference between the patient group and the control group in terms of having more than one club activity per month (p < 0.05). Conclusions It was found that the patients with ADHD are more aware of perceived negative aspects of the area in which they reside, thus reflecting their anxiety. In addition, it was also found that the patient group did not partake in as many social activities as the control group.

• 정보교육학회논문지
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• 제22권3호
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• pp.307-316
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• 2018

본 연구는 초등학교에서 로봇 활용 SW 교육을 실시하여 학생들의 CT, 로봇에 대한 태도에 미치는 효과를 알아보고 보조 교사 유무에 따른 차이를 알아보고자 하였다. 이를 위해 서울의 A 청소년수련관의 로봇 활용 SW 교육에 참여한 초등학생 29명을 실험집단과 통제집단으로 나누고, 로봇 활용 SW 교육을 실시하였으며, 수집된 자료는 대응 표본 t검정, 공분산분석을 통해 평균의 차이를 분석하였다. 연구 결과, 로봇 활용 SW 교육을 실시한 후 학생들의 CT와 로봇에 대한 태도가 유의하게 향상되었으나, 통제집단의 CT는 유의하게 향상되지 않았다. 또한 보조 교사 유무에 따른 사후 CT의 차이는 유의하였으며, 로봇에 대한 태도의 차이는 유의하지 않은 것으로 나타났다. 본 연구는 로봇 활용 SW 교육의 효과를 검증하고, 보조 교사 유무에 따라 차이가 있는지 규명하여 로봇 활용 SW 교육에 대한 이해를 확장시켰다는 점에서 연구의 의의를 찾을 수 있다.

• 융합정보논문지
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• 제9권12호
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• pp.81-87
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• 2019

대학생의 건강행위를 중심으로 건강관련 삶의 질 및 관련요인에 있어 성별에 따른 차이를 알아보고자 본 연구를 시도하였다. 삶의 질 측정도구로는 문화적 배경을 반영하여 개발된 KQOLS(Korean health related Qualtiy of Life Scale)l을 이용하였으며 D지역 남녀대학생 115명을 대상으로 자기기입식 설문조사를 시행하였다. 연구 결과 남성의 삶의 질이 여성에 비해 높았으나 통계적으로 유의한 차이는 없었고, 삶의 질 하부요인인 신체적 기능, 활력, 정신적 건강, 영적 건강은 남성이 여성에 비해 통계적으로 유의하게 높게 나타났다. 성별에 따른 삶의 질 영향요인 차이 분석에서는 남성의 경우 삶의 질 영향요인으로 질병유무(t=-2.118, p<.05), 규칙적 운동(t=2.346, p<.05), 정상 비만도(t=2.274, p<.05)가 포함되었으며, 이들 변수는 남자 대학생의 삶의 질을 약 25.1% 설명하였다. 반면에 여성에서는 건강행위가 삶의 질을 설명하지 못하는 것으로 나타났다.

• 말소리와 음성과학
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• 제6권4호
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• pp.91-99
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• 2014

Speaking styles tend to have an influence on spectral characteristics of produced speech. There are not many studies on the spectral characteristics of speech because of complicated processing of too much spectral data. The purpose of this study was to examine spectral characteristics and formant bandwidths of English vowels produced by nine American males with different speaking styles: clear or conversational styles; high- or low-pitched voices. Praat was used to collect pitch-corrected long-term averaged spectra and bandwidths of the first two formants of eleven vowels in the speaking styles. Results showed that the spectral characteristics of the vowels varied systematically according to the speaking styles. The clear speech showed higher spectral energy of the vowels than that of the conversational speech while the high-pitched voice did the same over the low-pitched voice. In addition, front and back vowel groups showed different spectral characteristics. Secondly, there was no statistically significant difference between B1 and B2 in the speaking styles. B1 was generally lower than B2 when reflecting the source spectrum and radiation effect. However, there was a statistically significant difference in B2 between the front and back vowel groups. The author concluded that spectral characteristics reflect speaking styles systematically while bandwidths measured at a few formant frequency points do not reveal style differences properly. Further studies would be desirable to examine how people would evaluate different sets of synthetic vowels with spectral characteristics or with bandwidths modified.

• 안보군사학연구
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• 통권4호
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• pp.157-209
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• 2006

The kinds of traits and behaviors studied most frequently in the early leadership research included physical characteristics, personalities, abilities, skills, behaviors and so forth. Researchers who studied leadership emphasized the important role of cultural, counter-insurgent, stability operational and clinical leadership traits and behaviors to perform the special mission of Overseas Forces The purpose of this study was to examine effective leadership traits, behaviors and skills for special mission of ROK Overseas Forces and to find out the differences on leadership traits, skills and behaviors among officers, noncommissioned officers(NCO) and enlisted men of the army. In order to achieve this purpose, a number of literature reviews and survey researches were conducted. The data for the analysis were collected through the questionnaire which consisted of 94leadership traits, skills and behaviors items Subjects were composed of 43 officers, 144 NCOs and 109 enlisted men Although the ranking order of leadership traits, skills and behaviors items among the groups for each analysis did not show much difference, the results of one-way analysis of variance revealed that a few items had a significant statistical difference among the groups. Implications of comparative results were also discussed in this study. In conclusion, this study would be useful basis for further improvement on effective leadership traits, skills and behaviors of ROK Overseas Forces, and some further researches were recommended.

• 치위생과학회지
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• 제17권3호
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• pp.267-274
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• 2017

This study aimed to compare the effectiveness of chewable toothbrush and manual toothbrush and provide basic data for recommendation of the chewable toothbrush in specific groups and situations. A total of 20 subjects participated in this study (rolling method, 10; non-rolling method, 10). After professional prophylaxis, participants used the manual toothbrush to brush their teeth for 3 minutes. After a 7-day wash-out period, participants used the chewable toothbrush according to the manufacturer's instructions. Pre- and post-plaque indexing of the teeth was performed. The dental plaque index was assessed using the Turesky Modification of the Quigley-Hein Plaque Index (TMQHPI) for amount of plaque and Silness-Loe Plaque Index (SLPI) for plaque thickness. The difference between pre- and post-dental plaque index was analyzed using a paired t-test and the Wilcoxon signed-rank test. The Mann-Whitney U test was also used to compare the dental plaque index reduction rates. The dental plaque index differed significantly between the chewable toothbrush and the manual toothbrush. The TMQHPI reduction rate was significantly different between the rolling and non-rolling method groups for the manual toothbrush but not the chewable toothbrush. The difference in SLPI reduction rate between the rolling and non-rolling method groups was significant for the manual toothbrush but not for the chewable toothbrush. Differences in the dental plaque index reduction rates between the chewable and manual toothbrushes were not significant in the non-rolling method group. The results of this study showed higher reduction rates in dental plaque with manual toothbrush use than with chewable toothbrush use. However, the non-rolling method group did not show statistically significant differences according to toothbrush type. The present study showed that a chewable toothbrush can be an alternative to a manual toothbrush for individuals who have difficulty using the generally recommended rolling method.