• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.4
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• pp.613-618
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• 2009

Impacted molars are not usual with the prevalence rate of less than 1%, however problems such as infraocclusion, extrusion of the opposite tooth and lack of space are caused. If molars are impacted, radiographic check-up and observations are needed as they play an important role in skeletal development and mastication. Causes of impaction are underdevelopment of roots, supernumerary teeth, cysts, odontomas, ankylosis and etc. In our first case, we present impacted molar which was surgically exposed and orthodontically traded. As the developmental state of the root was less than half at first visit, we observed until the root was 2/3 in its length and traction was carried out. The second case is orthodontic traded molar with compleate enucleation of the existing cysts. When trading impacted molars, direct bonding of attachments to the tooth and light continuous forces are recommended so as to ankylosis, external absorption and periodontal attachment loss avoid. Fixed appliances tract the teeth on arch and obtain eruption spaces without patient's cooperation. We report surgically exposed and orthodontically traded molars which resulted in good occlusion and patients satisfaction.

• Tunnel and Underground Space
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• v.27 no.4
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• pp.230-242
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• 2017

Seismic velocities measured from in-situ tests (n=177) and through rock core samples (n=1,035) are reviewed in light of construction standards, widely used standards as a first-hand approximation of rock classification solely based on seismic velocities. In-situ down hole tests and refraction survey for soft rocks showed seismic velocities of 1,400~2,900 m/s which is faster than those specified in construction standards. For moderate~ hard rocks, in-situ down hole tests and refraction survey showed 2,300~3,800 m/s which roughly corresponds with the range specified in the construction standards. A similar trend is also observed for seismic velocities measured from rock core samples. The observed differences between construction standards and seismic velocities can be explained in two ways. If construction standards are correct the observed differences may be explained with seismic velocities affected by underlying fast velocities and also possibly with selection of intact cores for velocity measurement. Alternatively, construction standards may have intrinsic problems, namely artificial discrete boundaries between soft rocks and moderate rocks, application of foreign standards without consideration of geologic setting and lack of independent verification steps. Therefore, we suggest a carefully designed verification studies from a test site. We also suggest that care must be exercised when applying construction standards for the interpretation and accessment of rock mass properties.

• Journal of dental hygiene science
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• v.12 no.6
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• pp.566-571
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• 2012

Marginal and internal fit are very important factor for the clinical long-term success of fixed dental prostheses (FDPs). A variety of methods have been applied to the measuring marginal and internal fit of FDPs. The purpose of this study was to compare the marginal and internal fit of 2 different measuring methods silicone replica technique [SRT] and die cutting technique (DCT). SRT, the space between die and FDPs were filled with light-body silicone, then stabilized by medium-body silicone. DCT, the FDPs were cemented on definitive dies and embedded into epoxy. The silicone replicas and epoxies were sectioned mesio-distal and measured 4 locations (margin, rounded chamfer, axial, occlusal) and using a digital microscope at a magnification $\times$160. For the SRT the mean${\pm}$SDs fit (${\mu}m$) recorded were: margin $88.7{\pm}22.2$, rounded chamfer $90.6{\pm}25.0$, axial wall $61.5{\pm}21.8$, occlusal $134.9{\pm}30.8$. For the DCT the mean${\pm}$SDs fit (${\mu}m$) recorded were: margin $85.3{\pm}18.0$, rounded chamfer $85.4{\pm}24.7$, axial wall $62.0{\pm}21.3$, occlusal $131.7{\pm}30.5$. The mean${\pm}$SDs size (${\mu}m$) of SRT margin was $88.7{\pm}22.2$ and of DCT margin was $85.3{\pm}18.0$. There were no statistically significant difference (p<0.05) of the four parts between SRT and DCT. It is considered an appropriate case to use SRT at fit of FDPs.

• The Mathematical Education
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• v.58 no.1
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• pp.101-120
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• 2019

The goal of this study was to apply an expectancy-value model(Wigfield & Eccles, 2000) to explain changes in six multi-ethnic students' achievement motivation in mathematics during sixth (2012) to eighth (2014) grades. In order to achieve this goal, we used narrative research methods. Although individual students' achievement motivation and mathematics related life experiences differed, there are some common factors influencing their motivation development, especially (a) roles played by parents and teachers; (b) assessment of peers' competencies; (c) past learning experiences related to mathematics curriculum; (d) perception of the relationship between mathematics competency and other subjects; (e) home backgrounds; and (f) perceived task values. In this study, we achieved some insight into why some multi-ethnic students are willing to study hard to get good scores while others are uninterested in mathematics, and why some multi-ethnic students are likely to pursue new mathematical tasks and persist despite challenges, while others easily give up studying mathematics in the face of adversity. We argue that in order to increase and sustain multi-ethnic students' achievement motivation, educators and parents should recognize that motivation is contextually formulated in the intersection of current people, time, and space, not a personal entity formed in an individual's mind. The findings of this study shed light on the development of achievement motivation and can inform efforts to develop multi-ethnic students' positive motivation, which might influence their mathematics achievement and success in school.

• Journal of Popular Narrative
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• v.25 no.4
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• pp.135-158
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• 2019

The purpose of this paper is to elucidate the characteristics that make Guillermo del Toro's film Pan's Labyrinth (2006) a fantasy film, and the meaning and function of the labyrinth motifs closely related to it. Tzvetan Todorov defined the 'fantastic' as the hesitation between natural and supernatural interpretations in the face of supernatural events that invade reality. In Pan's Labyrinth, the fantastic continues to be seen, because the film does not allow the hesitation to disappear; thus, the fantastic does not enter the 'uncanny' genre or 'marvelous' genre, and because it keeps its fantastic state. In this case, the labyrinth symbolizes art as a passage into the fantastic world and a space that represents it. Rosemary Jackson saw the fantasy as a "literature of desire to compensate for a lack resulting from cultural constraints" and thus repeatedly dealing with unconscious materials. Del Toro's film shows the character of the fantastic as an expression of desire by allowing 'family romance' to take place in the fantastic world. In this case, the labyrinth symbolizes the mind as a place of desire. Kathryn Hume defined fantasy as a reaction to reality, like mimesis, and 'departure from consensus reality.' The film, operating in a 'vision' genre, satisfies its definition by allowing the fantastic world to illuminate the reality world through 'contrastive' technique, and brings out the fantastic it has. In this case, the labyrinth symbolizes the world as a mirror of the world of reality. Thus, Pan's Labyrinth is representative of fantastic film in that the fantastic functions very effectively, and the labyrinth appearing in this film can be evaluated as a motif that is full of meaning by symbolizing all three elements of art, world and mind. The significance of this paper is to shed light on how a motif works in a particular genre through the above considerations.

• The korean journal of orthodontics
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• v.18 no.2
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• pp.311-327
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• 1988

Vascular changes in the periodontal ligament of the rat incisors following application of experimental orthodontic forces were examined by the India ink perfusion method. 57 rats were used for this experiment. The rats were divided into experimental group (54 rats) and control group (3 rats). 54 experimental rats were divided into group I (27 rats) and group II (27 rats). The right and left upper incisors of group. I and group II rats were separated distally with forces of 20gm, 70gm respectively. The vascular changes of periodontal ligament were observed histologically by means of light microscope after 1, 2 and 3 days of tooth movement and 1,3,5,8,14, and 21 days after removal of orthodontic force. The results were as follows; 1. After one day of tooth movement, occlusion of blood vessels, hyalinization of periodontal ligament and resorption of alveolar bone adjacent to the alveolar crest on pressure side were observed. Above the tissue changes on the pressure side of group II were more severe than those of group I. Especially, septal bone of group II was separated after 2 days of tooth movement. 2. In tension zones, periodontal space was widened and periodontal fibers were orientated in the direction of puil. The blood vessels of periodontal ligament were distended. New bone deposition was seen along the inner surface of the alveolus after 2 days of tooth movement. 3. After 3 days of tooth movement, deposition of new bone was seen along the periosteal surface of alveolar bone on pressure side, progressing with increasing after removal of orthodontic force. Remodelling of the new bone was occurred 5 days after removal of orthodontic force. 4. 3 days after removal of orthodontic force, invasion of blood vessels into the marginal periodontal ligament on pressure side was observed clearly and the vessels below the epithelial attachment were increased. 5. After removal of orthodontic force, hyalinized structures disappeared concomittantly with an invasion of blood vessels from the neighboring periodontal ligament. 14 days after removal of orthodontic force, the vessels in the periodontal ligament of group I were finished the vascular rearrangement. 21 days after removal of orthodontic force, the vessels in the periodontal ligament of group II were finished the vascular rearrangement.

• Cartoon and Animation Studies
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• s.33
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• pp.449-467
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• 2013

Contemporary 21st century, the rapid development of technology has achieved due to the emergence of various digital devices, a variety of media to the diversification of the limits of visual representation is reduced. Therefore, the combination of technology and art, visual arts, giving limits of getting it free to the public will feel fresh new visual impact. Such a new approach to light of a combination of technology and art, a variety of fine art and motion picture of the visual arts, such as has been recognized as a new genre. Of the resolution of the projector by utilizing the current reality and unreality beyond the boundaries of the building or structure in the city, as a schematic design of the screen projected structure and mapping of the art technology in an attempt to integrate recent has been studied in various ways. The projected structure design and the mapping of the art technology in an attempt to incorporate recent research has been diverse. In this study, as a new technology of a projection mapping to study the technique of looking for the definition of mapping practices to maximize the effectiveness of Visual Perception 3D animation was applied to a case study. A combination of 3D animation and project mapping in the future the fusion of art and technology to meet the zeitgeist with new possibilities of visual art to create synergies that is expected.

• Journal of the Korean Institute of Landscape Architecture
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• v.44 no.5
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• pp.47-58
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• 2016

In modern era Busan, newspaper articles about cherry blossom attractions from FuzanNippo and ChosenJiho have changed from places of landmark cherry trees to recreational activities under the cherry blossom. This means that the place characteristics of the cherry blossom attractions helped transform modern Busan. This study is to clarify the real image of the cherry blossom attractions where they were and when it was established in modern Busan. In order to discuss the location characteristics and the timing of identification as it changed from cherry-blossom viewing spots to picnic spots under the cherry blossom, current articles published in the FuzanNippo and ChosenJiho were collected. This study results are as follows: First of all, cherry blossom attractions are located in private gardens, gardens at hot spring inns, public lands such as schools, temples, reservoirs and malls such as Dongnae hot spring and the Midoricho red-light district. The location feature was that they were found at the edges of settlement environments, at the interface of city and natural spaces in modern Busan. Secondly, newspaper articles about cherry blossom attractions gradually changed from cherry blossom viewing spots to picnic spots under the cherry blossom, which became the peak of the cherry blossom attractions in modern Busan. The main focus of cherry blossom attractions changed from cherry-blossom viewing to picnicking under cherry blossoms around 1920. This means that the establishment of cherry blossom attractions can be seen around 1920. Articles of cherry-blossom viewing picked up sites not easy to access such as private gardens and reservoirs, articles about picnic spots under cherry blossoms noted public places that everyone could access. Cherry blossom attractions sites became spring resorts in modern Busan.

• Applied Chemistry for Engineering
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• v.21 no.5
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• pp.522-526
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• 2010

Heat storage application techniques can be categorized into the sensible heat storage and the latent heat storage according to the method of heat storage. Heat storage is the way of saving remaining heat when heating and cooling loads are light, and then using it when the heating and cooling loads are heavy. Latent heat storage is defined as the method of saving heat by using substances which have high potential heat when phase change is in the range of a certain temperature and when heat storage space is small, compared to those of sensible heat storage and it is possible that absorption and emission of heat at a certain temperature. This study is conducted to save energy when either air-conditioning or heating is operated in a building. We have tried to find out the essential properties of matter and the optimum mixing rate about cement and gypsum for building materials, which have been widely used for proper phase change materials (PCM), when thermal environment property is applied. So we obtained the result of the cooling delay effect about 19% with heat storage mortar containing 3 wt% of PCM.

• Magazine of the Korean Society of Agricultural Engineers
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• v.24 no.1
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• pp.31-43
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• 1982

Engineering phase of dairy housing systems has close connection with the milk produc- tivity of dairy cattle, the quality of milk, extension of dairy production systems, labor- saving in management of dairy cattle and the like. Moreover, the rate of investment of dairy housing facilities is of relatively high level, However, there has been almost no research effort for the improvement of engineering aspects of dairy housing systems in Korea. The purpose of this study is to find out general engineering problems and to recomm- end the improvement in dairy housing systems in Korea. Field survey by means of questionaire, direct measurements, taking pictures and sketching was conducted to get necessary information for the study. Kyung-ki Do region was firstly chosen for sampling area since it has included more than half of the number of dairy farms of the whole country. The results obtained are summarized as follows: 1. In overall dairy farm layout, the dwellings of workers were ignored in the light of sanitary environment 2. The layout of stalls in a dairy barn belongs mostly to the type of double-row face-out, which is compatible with the emphasis of manure disposal activities. 3. While the width and length of stalls were sufficiently close to the standard dimension, the width of mangers was much less than the standard dimension. 4. The width and depth of manure gutters and the width of working alleys were much. less than the standard dimension. 5. The mooring equipment was mostly in the classes of chain or rope. The watering equipment was not facilitated independantly except the one cese of using watercup. 6. The bucket milkers with one or two bucket milkers with the capacity of two cattles. each were used as milking equipment in most dairy farms. 7. There were only few milk rooms independently spaced from other space, in which the arrangement of milking equipment was much less than the standard condition. 8. The lounging ground area was averaged to be sufficient for the activity of dairy herd. 9. Silos for silage used during winter consisted of mostly bunker silos, trench silos and underground vertical silos. Ordinary vertical silos were considered for the farmers to be inconvenient for the labor saving. 10. From the view point of heat conservation and moisture removal within the dairy barns, windows were not flexible for the easy ventilation and ceiling part was not adequate for temperatur maintenance. 11. Waste treatment and disposal systems were not provided with most dairy farms, therefore the livestock waste pollution problems would be serious in the near future.