• Title/Summary/Keyword: 연구유형분석

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A Posteroanterior Cephalometric Study on Craniofacial Proportions of Koreans with Normal Occlusion (한국인 정상 교합자의 정모 두부 방사선 사진을 이용한 안모비율에 관한 연구)

  • Baik, Hyoung-Seon;Yu, Hyung Seog;Lee, Kie-Joo
    • The korean journal of orthodontics
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    • v.27 no.4 s.63
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    • pp.643-659
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    • 1997
  • For the total treatment of skeletal malocclusions, 3-dimensional evaluation and diagnosis are essential. Although anteroposterior discrepancies can be evaluated through various methods, the satisfactory methods for evaluations of facial asymmetry and transverse discrepancies are yet to be found. The adequate diagnosis and treatment of transverse discrepancies may be more important in the maintenance of functional occlusion as well as for the stability of results obtained from orthognathic surgery than the anteroposterior or vertical discrepancies. Since the soft tissue effects from the transverse discrepancies may not be pronounced, especially when combined with anteroposterior or vertical discrepancies which have prominent characteristics, the differentiation of their effects may be difficult from visual inspection alone. Therefore it is essential that the normal facial proportions would be established from the posteroanterior cephalometry as a reference for the accurate diagnosis and treatment. The present study evaluates 76 subjects from Yonsei University freshmen with normal facial symmetry and occlusion. Posteroanterior cephalograms were taken from the subjects and the normal values and facial proportions are obtained. The results are as follows. 1. The transverse and vortical values from posteroanterior cephalometry and their ratio, with means and standard deviations are calculated. 2. The ratio of vertical values to transverse values is 0.837 (male 0.836, female 0.841). 3. The Proportion of maxillary and mandibular widths is 0.747 (male 0.745, female 0.752), with statistically significant correlation. 4. Various degree of significant correlations are observed in the following craniofacial widths; (Cranial width, Bizygomaticofrontal suture width, Facial width, Maxillary width, Upper & Lower Intermolar width, Mandibular width). 5. Although the facial height as well as other line measurements increase as the facial widths increase, angle measurement ($Bj\ddot{o}rk$ Sum, Mandibular Plane Angle, Gonial Angle), decreases and posterior to anterior facial height ratio increases, therefore indicating the tendency for a brachycephalic facial type. These results may be used as references for the treatment planning in orthognathic and orthodontic treatments for the dentofacial deformity patients.

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The Characteristics of Perceptual Change of High School of the Arts Students through Explicit Instructions on the Nature of Science (예술 고등학생들의 명시적 과학의 본성 수업을 통한 개념 변화의 특성)

  • Kim, Hee-Jung;Kim, Sung-Won
    • Journal of The Korean Association For Science Education
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    • v.33 no.2
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    • pp.266-283
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    • 2013
  • The goal of this study is to explore the characteristics of perceptual change among students majoring in arts on the nature of science and apply the results to science education. According to the study, it is important to consider the results of interaction between learners' aptitude and teaching method. Teaching the nature of science to first grade students explicitly, experimental inquiry strategy was applied to fine arts students, and teaching strategy of scientific history to music students. To find out which elements of the nature of science have come into view on modern philosophy of science, pre and post tests on the nature of science (VNOS-C) were conducted on the students. To find out specifically why views on the nature of science have changed, a case study was conducted focusing on students who showed changes in their views on the elements of the nature of science. In conclusion, this study suggests that by using experimental inquiry strategy and strategy of scientific history properly, it is possible to change students' viewpoints on the elements of the nature of science and on modern philosophy of science. Through explicit instruction, we were able to find some positive conceptual changes on the nature of science and the modern philosophy of science in terms of both quantity and quality. This shows that the students studying arts are experiencing a constructivist conceptual change on the nature of science, and that conceptual ecology and learning strategy are involved in this process. Therefore, it is thought that this study offers an important implication in organizing science education on the nature of science.

Improved Preservation Methods for Big and Old Tress in South Korea (우리 나라의 노거수자원(老巨樹資源) 보호관리실태(保護管理室態) 및 개선방안(改善方案))

  • Park, Chong-Min;Seo, Byun-Soo;Lee, Cheong-Taek
    • Journal of Korean Society of Forest Science
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    • v.89 no.3
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    • pp.440-451
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    • 2000
  • This study was conducted in order to provide essential data and relevant management proposal to conserve and maintain big and old trees in a rational way. For the field survey, 77 big and old trees preserved by the laws in Chollabuk-do, Korea were investigated. The study results are summarized as follows : 1. To conserve and manage big and old trees, the valuable trees have been designated as natural monument trees and protection-needed trees. There are 141 individuals of 37 species designated as natural monuments and 10,049 individuals of 102 species designated as protection-needed trees. 2. Management budget for natural monument trees was devoted at 70% from the national expenditure, but that for protection-needed trees was devoted at 98% from the local expenditure. 3. Standardized sign boards and sign stones for natural monument trees were well placed and other protection facilities such as fences, branch supports and branch holdings were established. On the other hand, management of protection-needed trees was deficient overall. 4. Problems for designation process and management of protection-needed trees could include items such as insufficient management budget, various development activities, land ownership, misjudgement of tree age and species identification, unsatisfaction of sign board placement, insufficient surgery for damaged trees, pavement around tree root system and environmental pollution around the trees. 5. In order to improve the existing management methods of big and old trees, the following schemes were suggested : the development of practical criteria for natural monument and protection-needed trees, nationwide surveys of big and old tree resources, the security of national budget, securing sufficient spaces for the tree growth, specialization of management systems, extended practices of tree form management, establishment of permanent standard signs and consideration of opinions of village residents.

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A Study on the Use of Wintering Habitats of Water Birds Arriving at Coastal Wetlands in Jeollanam Province, Korea (전라남도 연안습지에 도래하는 수조류의 월동지 이용에 관한 연구)

  • Choi, Young-Bok;Jung, Sook-Hee;Yoo, Seung-Hwa;Kang, Tae-Han;Lee, Han-Soo;Paek, Woon-Kee;Choi, Chung-Gill;Kim, In-Kyu
    • Korean Journal of Environment and Ecology
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    • v.21 no.3
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    • pp.197-206
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    • 2007
  • This study was conducted to survey the population of water birds wintering at the seven coastal wetlands of Jeollanam province including Suncheon Bay and Yeongsan Lake, from 2000 through 2003. The 90 species and 857,570 individuals in total were sighted at the seven survey sites. We classified the wintering water birds into seventeen groups of taxa based on the similar ecological attributes, among which, eight groups were found to inhabit the water surface or riparian areas. Classified groups that showed higher rate of using bay areas than that of lake areas were in the order of waders, gulls and swans. On the other hand, the groups that showed higher rate of using lake areas than that of using bay areas were revealed in the order of dabbling ducks, grebes and geese. In conclusion, there was a difference in the pattern between the two classified groups. As a result of the UPGMA cluster analysis using CCs ($S{\varnothing}rensen'a$ index of similarity and Ro (Horn's index of community overlap), the results showed that Suncheon Bay had the most unique species formation out of the seven areas. Bay and lake areas were different from each other in the formation of species and Individuals. As a result of combining the index rank according to the maximum aggregate count, the Suncheon Bay is ranked the highest in importance of the habitats for water birds, followed by the order of Boseong-Deukryang Bay, Gangjin Bay, Gocehongam Lake, Geumho Lake, Yeomam Lake, and Yeongsan Lake. Considered overall, the importance of the bay areas was relatively higher than that of reclaimed lake areas.

Vegetational Structure and the Density of Thinning for the Inducement of the Ecological Succession in Artificial Forest, National Parks - In Case of Chiaksan, Songnisan, Deogyusan, and Naejangsan - (국립공원 인공림 식생구조 및 생태적 천이 유도를 위한 간벌 밀도 연구 - 치악산, 속리산, 덕유산, 내장산을 사례로 -)

  • Kim, Jong-Yup;Lee, Kyong-Jae
    • Korean Journal of Environment and Ecology
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    • v.26 no.4
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    • pp.604-619
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    • 2012
  • According to the concept of woodland aesthetic in Germany and forest design in United Kingdom, artificial forest should be restore ecologically step by step in National Park, Korea. This study was carried out to provide the density criterion of thinning for the inducement of the ecological succession by analysing of vegetational structure in Artificial Forest, National Parks. Eleven plots(size is $20m{\times}20m$) were set up in the artificial forest such as Pinus koraiensis forest, Abies holophylla forest, Chamaecyparis obtusa forest, Populus tomentiglandulosa forest, and Larix kaempferi forest and in the natural forest such as Pinus densiflora community, Pinus densiflora-Quercus serrata community, and Quercus serrata community in Chiaksan, Songnisan, Deogyusan, and Naejangsan National Parks, Korea. We classified the artificial forest into undeveloped type of succession, type of alien young trees developing, and early phase type of succession based on the vegetational structure. According to the index of Shnnon's diversity(unit: $400m^2$), undeveloped type of succession was ranged from 0.9681 to 1.1323, type of alien young trees developing was ranged from 1.0192 to 1.1870, early phase type of succession was ranged from 1.3071 to 1.3892, and natural vegetation was ranged from 1.2202 to 1.3428, therefore early phase type of succession forest and natural vegetation are more higher than simple-layered artificial forest with one needle leaf tree species. The limit for the step-by-step thinning was in the range of 30~60%. In case of undeveloped type of succession, we should thin out from large trees throughout three phases, because alien species dominated high value 88~90% in canopy layer. In case of type of alien young trees developing, we should thin out from alien young trees such as Populus tomentiglandulosa throughout one or two phases, because alien species dominated high value 60~97% and young trees with saplings growing up in understory and shrub layer. In case of early phase type of succession, we should thin out from alien trees that compete with native species throughout one or two phases, because alien species dominated less than value 30%.

Evaluation of Autonomic Neuropathy in Patients with Sleep Apnea Syndrome (수면 무호흡 증후군 환자에서 자율 신경 장애의 평가)

  • Lee, Hak-Jun;Park, Hye-Jung;Shin, Chang-Jin;Kim, Ki-Beom;Chung, Jin-Hong;Lee, Kwan-Ho;Lee, Hyun-Woo
    • Tuberculosis and Respiratory Diseases
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    • v.45 no.2
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    • pp.404-415
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    • 1998
  • Background: Sleep apnea syndrome, which occurs in 1~4 % of the adult population, frequently has different cardiovascular complications such as hypertension, ischemic heart disease, cardiac arrythmia as well as sleep-wake disorder such as excessive daytime hypersomnolence or insomnia. Mortality and vascular morbidity are reported to be significantly higher in sleep apnea syndrome patients than in normal population. According to the recent studies, autonomic dysfunction as well as hypoxemia, hypercapneic acidosis, and increased respiratory effort, may playa role in the high prevalence of cardiovascular complications in patients with sleep apnea syndrome. However the cause and mechanism of autonomic neuropathy in patients with sleep apnea syndrome are not well understood. We studied the existence of autonomic neuropathy in patients with sleep apnea syndrome and factors which influence the pathogenesis of autonomic neuropathy. Method: We used the cardiovascular autonomic neuropathy(CAN) test as a method for evaluation of autonomic neuropathy. The subjects of this study were 20 patients who diagnosed sleep apnea syndrome by polysomnography and 15 persons who were normal by polysomnography. Results: Body mass index and resting systolic blood pressure were higher in sleep apnea group than control group. Apnea index(Al), respiratory disturbance index(RDI) and snoring time percentage were significantly higher in sleep apnea group compared with control group. But there were no significant differences in saturation of oxygen and sleep efficiency in two groups. In the cardiac autonomic neuropathy test, the valsalva ratio was significantly low in sleep apnea group compared with control group but other tests had no differences between two groups. The CAN scores and corrected QT(QTc) interval were calculated significantly higher in sleep apnea group, but there were no significant correlations between CAN scores and QTc interval. There were no significant data of polysomnography to correlate to the CAN score. It meant that the autonomic neuropathy in patients with sleep apnea was affected by other multiple factors. Conclusion: The cardiovascular autonomic neuropathy test was a useful method for the evaluation of autonomic neuropathy in patients with sleep apnea syndrome and abnormalities of cardiovascular autonomic neuropathy were observed in patients with sleep apnea syndrome. However, we failed to define the factors that influence the pathogenesis of autonomic neuropathy of sleep apnea syndrome. This study warrants futher investigations in order to define the pathogenesis of autonomic neuropathy in patients with sleep apnea syndrome.

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Teachers' Importance Perception of the Contents in Housing Unit of Middle School Technology and Home Economics Subject (중학교 기술 가정 교과의 주생활단원 내용에 대한 교사의 중요도 인식)

  • Jun, Kyung-Sook
    • Journal of Korean Home Economics Education Association
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    • v.20 no.4
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    • pp.223-237
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    • 2008
  • The purpose of this research was to provide the information needed for improving the contents in housing unit of middle school technology and home economic textbook. For this purpose, a survey questionnaire was developed to examine teachers' importance perception of 48 contents in housing unit. A direct survey and an e-mail survey were used to collect data from teachers, and a total number of 233 data were analyzed. Conclusions were summarized as following: 1. Among the 48 contents in housing unit, the average score of teachers' importance perception of the 18 contents on 'interior environment and equipments' was 3.94; the average score of teachers' importance perception of the 15 contents on 'living space plan and use' was 3.78; and the average score of teachers'importance perception of the 15 content on 'housing maintenance and repair' was 3.42. Therefore, the 15 contents on 'housing maintenance and repair' must be revised. 2. Teachers' importance perception of 25 contents, among the 48 contents in housing unit, were significantly differentiated by gender, age, teaching experience, scholastic attainment, subject in charge(technology, home economics, technology and home economics), school type(boys' middle school, girls' middle school, coeducation), and region(city, county). Therefore, the 25 contents, of which importance perception were influenced by teachers' characteristics, must be revised in order to maintain the consistent importance perception. Suggestions were that the team teaching of technology and home economic textbook was more recommendable; that the local situations must be considered in the contents of housing unit and; that the contents of housing unit must be segmented into a minimum unit for the accurate evaluation.

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An Analysis of Terrorism against Korea to Overseas and its Implications - Focusing on the companies advancing to overseas - (한국을 대상으로 한 국제테러리즘의 분석과 시사점 - 해외진출기업을 중심으로 -)

  • Chang, Suk-Heon;Lee, Dae-Sung
    • Korean Security Journal
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    • no.28
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    • pp.153-179
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    • 2011
  • Korea has been a victim of State supporting terrorism by North Korea even before international society realize the terrorism threats because of 9.11 in US. However, state supporting terrorism against South Korea by North Korea went along with East/West Cold War System by US and the Soviet Union. It is because socialism that Kim Il-sung who established a separate government in North Korea with the political, economic, social and military support of the Soviet Union selected as his political ideology justifies terrorism as the tool to complete the proletariat revolution. North Korea's state supporting terrorism is being operated systematically and efficiently by military of North Korea. It gives big worries to international society not only by performing terrorism against Korea but also by dispatching terrorists and exporting terrorism strategies to the third world countries. In this situation, terrorism against Korea has met a new transition point at 9${\cdot}$11 in US. As South Korea is confronting North Korea and the war has not ended but suspended, the alliance between US and Korea is more important than anything else. Because of this Korea decided to support the anti-terrorism wars against Afghanistan and Iraq of US and other western countries and send military force there. The preface of the anti-terrorism war has begun as such. On October 7, 2001, US and UK started to attack Afghanistan and Taleban government in Afghanistan was dethroned on December 7, 2001. US and western countries started a war against Iraq on March 20, 2003. On April 9, 2003 Baghdad, the capital of Iraq fell, and Saddam Hussein al-Majid al-Awja government was expelled. During the process, the terrorism threat against South Korea has expanded to Arab terrorists and terrorism organizations as well as North Korea. Consequently, although Korean government, scholars and working level public servants made discussions and tried to seek countermeasures, the damages are extending. Accordingly, terrorism against Korean companies in overseas after 9${\cdot}$11 were analyzed focusing on Nation, Region, Victimology, and Weapons used for the attacks. Especially, the trend of terrorism against the Korean companies in overseas was discussed by classifying them chronologically such as initiation and termination of anti-terrorism wars against Afghanistan and Iraq, and from the execution of Iraqi President, Saddam Hussein al-Majid al-Awja to December 2010. Through this, possible terrorism incidents after the execution of Osama bin Laden, the leader of Al-Qaeda, on May 2, 2011 were projected and proposals were made for the countermeasures.

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Evaluation of Ecological quality and establishment of ecological restoration guideline in landscape level of Mt. Moodeung National Park (무등산국립공원의 생태적 질 평가 및 복원 가이드라인 수립)

  • Lim, Chi Hong;Park, Yong Su;An, Ji Hong;Jung, Song Hie;Nam, Kyeong Bae;Lee, Chang Seok
    • Korean Journal of Ecology and Environment
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    • v.49 no.4
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    • pp.296-307
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    • 2016
  • Ecological restoration is an eco-technology, which heals the nature damaged by human activity by imitating organization and function of the integrate nature and thereby provide an inhabitable space for diverse organisms. Such an ecological restoration has to be carried out by applying restoration plan prepared based on the results of diagnostic evaluation discussed in the diversified respects. This study aims to prepare an ecological restoration plan of the damaged forest ecosystem in Mt. Moodeung National Park. To arrive at the goal, first of all, we diagnosed quality of forest landscape established in Mt. Moodeung National Park based on natural (topography, climate, and distribution of vegetation) and artificial (land use, linear landscape element) factors. In addition, we evaluated the integrity of each zone divided by linear landscape element quantitatively based on geometric property and land use intensity. As the result of analysis, topography of Mt. Moodeung National Park tended to be depended on weathering property of parent rock and vegetation zones were divided to three vegetation zones. Based on land use pattern, deciduous broad-leaved forest, evergreen needle-leaved forest, and mixed forest occupied about 90% of Mt. Moodeung National Park. Mean score of forest landscape quality was shown in $69.86{\pm}11.41$. As a result, forest landscape elements in Mt. Moodeung National Park were influenced greatly by human activity and the degree was depended on topographic condition. This study suggested the synthetic restoration plan to improve ecological quality of Mt. Moodeung National Park based on the results of diagnostic evaluation.

Molecular Characterization and Toxin Profile of Bacillus cereus Strains Isolated from Ready-to-eat Foods (유통 중인 즉석·편의식품류에서 분리한 Bacillus cereus의 산생 Toxin 및 분자유전학적 특성 조사)

  • Kim, Tae Sun;Kim, Min Ji;Kang, Yu Mi;Oh, Geune;Choi, Su Yeon;Oh, Mu Sul;Yang, Yong Shik;Seo, Jung-Mi;Ryu, Mi-Geum;Kim, Eun-Sun;Ha, Dong-Ryong;Cho, Bae Sik
    • Korean Journal of Food Science and Technology
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    • v.46 no.3
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    • pp.334-340
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    • 2014
  • Toxin-producing Bacillus cereus is the causative agent of two different types of food poisoning: the emetic and the diarrheal types. This study was conducted to investigate the presence of enterotoxin and emetic toxin genes in 263 B. cereus isolated from 619 different ready-to-eat food items. Hemolytic enterotoxins hblA, hblC, and hblD were detected in 85.6, 41.1, and 76.8%, respectively, of the B. cereus isolates. About 67.0% (175/263) of the isolates presented all of three genes. Non-hemolytic enterotoxins nheA, nheB, and nheC were detected in 100, 97.0, and 68.4% of the isolates, respectively. Approximately 90.0% (236/263) of the isolates presented all of these three non-hemolytic enterotoxin genes. Emetic toxin gene, CER, was detected in 132 of 263 (50.2%) isolates. Computer-assisted cluster analysis of Rep-PCR profiles showed a high genetic diversity among the isolates. All B. cereus isolates from food samples tested in this study carried at least 6 of 10 toxin genes.