• Journal of the korean academy of Pediatric Dentistry
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• v.25 no.4
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• pp.683-690
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• 1998

The purpose of this study was to evaluate the reliablity of laser Doppler flowmeter on the permanent maxillary central incisors with open apex. Laser Doppler flowmeter and electric pulp tests were done in 35 elementary students aged between 8 and 9 years and 35 females and males aged between 23 and 24 years. Teeth with open apex were confined to root developmental stage 5 and 6 by Moorrees classification. The threshold of electric pulp tests was decided the time of tingling sensation. More than three different electric pulp tests applied on every teeth with more than 3 minutes interval between each teeth due to the false response. Laser Doppler flowmeter test stablilzation and observation stages took more than 5 minutes each LDF values and electric pulp test thresholds were analyzed with student t-test. The results were as follows: 1. The electric pulp test threshold on teeth with immature and mature roots showed 28.4% and 100% response respectively, and the the LDF values on teeth with immature and mature roots showed 100% response. 2. The EPT thresholds on teeth with immature roots were larger than thresholds on teeth with mature roots(p<0.01). 3. No significant differences were found in the LDF values on teeth with immature and mature roots.

• The korean journal of orthodontics
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• v.34 no.3 s.104
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• pp.241-251
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• 2004

Previous studies have focused on the causes of root resorption after orthodontic treatment and treatment methods to reduce this phenomenon, and have been mainly associated with developed, mature roots. As parents become increasingly interested in their children's' dentition, orthodontists are performing fixed orthodontic treatment on patients of less than 10 years and before the completion of the immature root. Thus, the author evaluated the changes of root length and root form of maxillary immature incisors after orthodontic treatment, compared with those of mature teeth, and investigated the correlation according to gender, treatment duration, and displacement of incisors. The sample consisted of an immature root group of twenty-eight persons (between 8 and 10 years old) and a mature root group of thirty-one persons (between 11 and 15 years old). The crown and root length of the maxillary four incisors were measured with a periapical radiograph, changes in root length and crown-root ratio were calculated, and root form was classified according to a scoring system. The results were as follows. 1. The development of immature roots was not affected by orthodontic treatment and mostly showed normal root length and apical form. 2. Root length of immature teeth was sustained or became shorter, partially in long treatment duration or with open bite patients. Even though the teeth reached their normal root length, they demonstrated a blunt form. 3. Most of the mature roots showed mild resorption, and the form of mature roots was more blunt than the developed form of the immature roots (p<0.05). 4. The developed form of the immature roots was statistically related to treatment duration, while the form of the mature roots was significantly related to the displacement of incisors (p<0.05). 5. In contrast, other variables such as gender, classification of malocclusion, changes in overbite, and changes of U1 to SN showed no correlation with the root resorption of both groups.

• Korean Architects
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• no.7 s.291
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• pp.44-49
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• 1993

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.2
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• pp.437-445
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• 1999

The purpose of this study was to evaluate the changes of laser doppler flowmeter output associated with stage of root development. Laser Doppler Flowmeter was done in 40 elementary students aged between 7 and 8 years and in 20 adults aged between 23 and 24 years. Among 40 elementary students, 20 had apical foramens with $1{\sim}2mm$ diameters and another 20 had ones with larger diameters than 2mm. The LDF values were analyzed with ANOVA and paired t-test. The results were as follows. 1. Immature root apecies group had a higher tendency than mature root apecies group in LDF values, but there was no statistical significance (p>0.05). 2. There was no statistical significance in LDF values comparing groups with immature root apecies (p>0.05). 3. There were no significant differences between right and left central incisors in LDF values (p>0.05).

• Journal of The Korean Association For Science Education
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• v.29 no.1
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• pp.1-9
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• 2009

The purposes of this study are to investigate the effects of the Science Conceptual Model Completion Activity and Science Conceptual Model Modifying Activity on middle-school students' achievement in science conceptual learning, and to analyze if there are any correlations among their achievements by purposed activities, their cognitive level and school science achievement. For the study, 112 middle school students were sampled for three groups, which are two experimental groups (Model Completion activity group, Model Modifying Activity group) and one control group. Pre- and post-tests were taken to measure the students' achievement in science concepts, and the logical thinking ability test was administered after the implementation period. In addition, their school science achievements were analyzed. The research findings are as follows: First, the Science Conceptual Model Completion activity is more effective for middle school students' science conceptual learning than the Science Conceptual Model Modifying activity or conventional activity. Second, higher school science achievement also results in higher achievement of science concepts through the Conceptual Model Modifying activity or the Conceptual Model Completion activity. Lastly, the Conceptual Model Completion activity is more effective for the concrete operational level students to attain science concepts than formal operational level ones. Meanwhile, on the contrary, the Conceptual Model Modifying activity is more effective for formal operational level students than the concrete operational level ones.

• The Inventors News
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• no.26
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• pp.6-6
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• 2004

특허를 받을 수 없는 미완성 발명 - 특허청, `특허고객 콜 센터` 특화상담원 상담 실시

• 건강소식
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• v.36 no.3
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• pp.30-31
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• 2012

자녀의 건강과 두뇌 성장을 별개라고 생각하면 안 된다. 자녀의 몸은 미완성이다. 불완전한 신체 조직은 서로 정보를 주고받으며 성장하기 때문에 두되는 건강 상태에 민감할 수 밖에 없다. 쉽게 말해, 머리 좋은 아이를 만드는 일은 건강한 아이를 만드는 일과 같다.

• 한국과학교육학회:학술대회논문집
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• 2008.01a
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• pp.128.1-128.1
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• 2008

• The Bimonthly Magazine for Agrochemicals and Plant Protection
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• v.7 no.5
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• pp.83-90
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• 1986

금년 벼농사에도 태풍에도 불구하고 막바지에 접어들어 풍년의 열매, 벼알이 황금물결로 변해가면서 온 들녘을 출렁이고 있다. 미완성된 쌀을 완전한 쌀로 만들어 6년 연속 풍년을 거두기 위해서는 앞으로도 실천해야 할 몇가지 핵심과제가 있는데 이 마무리작업을 착실히 실천하여 대풍농사를 거두도록 다같이 노력해야겠다.

• 전기의세계
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• v.23 no.3
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• pp.8-14
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• 1974

우리나라는 uranium광이 전연없어서 전적으로 외국에 의존할 수 밖에 없으므로 uranium의 이용도가 낮은 열중성자로보다는 고속로의 실용화로 그 만큼 자금면에서 이득을 얻게 될것이다. 현단계에서 고속로의 기술은 미완성이기 때문에 상업용원자로로는 열중성자로가 당분가 이용될것이지만 1970년대의 후반 또는 1980년대의 초반에 가서는 아마도 상업용고속증식로가 등장할것으로 예상되는 것이다. 이하 간단하게 원자로의 기본개념을 소개하고 고속로의 기술적 문제점 및 개발현황을 살펴본다.