• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.1
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• pp.109-116
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• 2010

Impaction is defined as a cessation of the eruption of a tooth caused by a clinically or radiographically detectable physical barrier in the eruption path or by an ectopic position of the tooth. The reasons for impaction of the maxillary central incisor are supernumerary tooth, odontoma, ectopic position of tooth germ, dilacerated tooth and so force. Impacted tooth cause space loss due to proximal movement of adjacent tooth, malocclusion, root resorption of adjacent tooth, cyst formation, so careful observation and early detection is important and exact treatment should be applied to prevent these results. The treatment options of impacted tooth include induction an eruption through extraction of deciduous tooth or surgical exposure, reposition of impacted tooth by surgical method or orthodontic treatment. Orthodontic traction is recommended when an eruption does not happen after removal of barrier or surgical exposure, when eruption path is too transpositioned to be corrected spontaneously so eruption does not expected. In these cases, traction of impacted maxillary central incisor was carried out using orthodontic method with closed eruption technique and it showed good clinical results so we report these cases.

• Journal of Korean Home Economics Education Association
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• v.21 no.1
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• pp.35-49
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• 2009

The purpose of this study was to examine the effect of instruction for the development of analytical rubrics based on teacher-student compromise, which would be applied to performance assessment about the ninth-grade housing unit of the 7th national curriculum. In order to find out the influence of the rubric development instruction on learning motivation, two different third-year classes in a middle school were selected respectively as an experimental group and a control group. The way of presenting the rubrics and learning motivation were respectively selected as independent and dependent variables. Both groups took two lessons and a pretest-posttest on learning motivation. As for the analytic rubric for the individual task performance in the housing unit, three evaluation items were selected. As a result, the instruction for the learner-involved development of analytical rubrics for the housing segment had a positive effect on the confidence and satisfaction of the middle schoolers, which were two out of four sub-factors of learning motivation. Open-ended questions showed that the instruction got to build confidence in the course of being aware of the evaluation criteria and fulfilling the given tasks.

• Journal of the Korean earth science society
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• v.30 no.2
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• pp.210-222
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• 2009

Lightning data, observed from total lightning detection system (TLDS) of KMA, for the recent five years (2002-2006) have been analyzed for temporal and spatial characteristics of frequency, intensity, duration, and flash rate. Lightning frequency varies largely with years (most frequent in 2006) and the lightning during the summer accounts for 75% of total flashes and only 0.6% of lightnings strike in cold season. In rainy season (JJAS), the ratio of positive flashes to negative ones is as low as 0.15, but it increases up to 0.98 in February. The seasonal variation of lightning duration is strongly linked with lightning occurrences, whereas flashes rates show weak seasonal variability. In a daily scale, lightning, on average, occurs more often at dawn (2 am, 5-7 am) and in the mid-afternoon (15 pm), and the lightning at dawn (around 5 am) is most intense during the day. The western inland areas md the West/South Sea show high lightning density during JJAS, whereas eastern part and the East Sea exhibit a low density of lightning. Considering the low ratio of positive flashes (0.15) for the whole analysis domain during summer period, Chungnam and Jeonbuk areas have a high ratio of flashes over 0.4. However, these should be analyzed with much caution because weak positive cloud-to-cloud discharges can be regarded as cloud-to-ground flashes. The western inland also exhibits long annual flash hours (15-24). And the W3st Sea has high flash rates as a result of large density and low flash hours. The most frequent time of lightning occurrence over most inland areas lies between mid-afternoon and early-evening, whereas mountainous and coastal areas, and the northern Kyoungki and Hwanghae provinces show the maximum lightning strikes in the morning and at dawn, respectively.

• Journal of the Economic Geographical Society of Korea
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• v.10 no.2
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• pp.93-115
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• 2007

As strategies for creating profits are differentiated by the national economic system and development strategies related to firms' geographical scope, they depend on the spatial contexts and product characteristics. In this perspective, strategies for the profit creation of Korean textile and clothing FDI firms invested in Vietnam has involved in the geographical differentiations in accordance with the development path of transitional economies, changes in institutional environments and the characteristics of products. Therefore. the main purpose of this research is to identify the way in which they have their own identity in transitional economies by investigating business pattern, commodity chain and extra-firm relations, which are related to institutional dynamics in Vietnam. There are two main characteristics of Korean textile and clothing FDI firms in Vietnam. The first is that all business activities involved in the commodity chain of them from R&D to production is controlled by global retailer and distributors, which is the buyer-driven commodity chain and the typical commodity chain of the textile and clothing industry. The second could be defined as over- or unforced embeddedness into the institutional legacy of the Soviet system, because they have been incorporated into pre-existing networks based on reciprocal relations in Vietnam.

• Tunnel and Underground Space
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• v.16 no.3 s.62
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• pp.251-258
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• 2006

In this paper, the applicability to the Korean rock condition of using the deformation moduli based on Rock Mass Rating (RMR) and Pressuremeter Test (PMT) is evaluated. The correlations among deformation moduli and various rock properties were also analyzed. It appears that the existing correlations using RMR overestimate the deformation moduli and wide variation was found between predicted moduli using these correlations and measured values. As for the correlations among the deformation moduli and various rock properties, Rock Quality Designation (RQD) and unconfined compressive strength (UCS) were found to correlate to deformation moduli reasonably well, but joint spacing and joint conditions appear to correlate poorly to RQD and UCS. Additionally, groundwater can not be correlated with the modulus values. While the depth has very little contribution to deformation modulus, it should be factored in the simple regression analyses with various rock mass properties, especially with the correlations made with UCS, RQD etc. With the deficiencies of these correlations, more in depth analysis techniques such as multivariate correlations may be to reliably estimate deformation modulus of rock mass.

• Journal of the Geological Society of Korea
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• v.54 no.6
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• pp.641-656
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• 2018

Although an amount of hydrocarbon has been discovered in the West Korea Bay Basin (WKBB), located in the North Korean offshore area, geophysical investigations associated with these hydrocarbon reservoirs are not permitted because of the current geopolitical situation. Interpretation of satellite derived potential field data can be alternatively used to image three-dimensional (3D) density distribution in the sedimentary basin associated with hydrocarbon deposits. We interpreted the TRIDENT satellite-derived gravity field data to provide detailed insights into the spatial distribution of sedimentary density structures in the WKBB. We used 3D forward density modeling for the interpretation that incorporated constraints from existing geological and geophysical information. The gravity data interpretation and 3D forward modeling showed that there are two modeled areas in the central subbasin that are characterized by very low density structures, with a maximum density of about $2,000kg/m^3$, indicating some type of hydrocarbon reservoir. One of the anticipated hydrocarbon reservoirs is located in the southern part of the central subbasin with a volume of about $250km^3$ at a depth of about 3,000 m in the Cretaceous/Jurassic layer. The other hydrocarbon reservoir should exist in the northern part of the central subbasin, with an average volume of about $300km^3$ at a depth of about 2,500 m. A comparison between the TRIDENT derived gravity field and the ship-based gravity field measured in 1980s shows us that our results are highly reliable and there is a very high probability to detect another low-density layer existings in the northwestern part of the central subbasin.

• 기호학연구
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• no.57
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• pp.155-176
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• 2018

This article is a study of Karl Marx's manifesto and the reform in donghak for the modality and their symbolism. As a text, Karl Marx and Friedrich Engels' declaration on the Communist Alliance and the reform program of the peasant Donghak were choose. This Declaration and the Reformation are the works of philosophical practice discourse of the 1800s in this article, which unfolds paradigmatically, deriving its common symbolic meaning in the semiotic sense, and evolving ideologically towards a democracy free of property. In the end, these two historical incident which are published in the contemporary breath, constitute an accusation against a nonhuman policy of surveillance and punishment. Twice a day, the space of the church is transformed into a factory, the act of dividing into two categories by capitalist and work and divorcing by accident is embodied as a social ethic. It is against the phenomenon that the structure of which no man exists is no longer institutionalized. The revolutionary movement aimed at breaking the framework of this hunt manifests itself in the two manifestos mentioned above, and Karl Marx completes the culmination of the utopia that must be achieved through the Declaration of the Communist Alliance by placing his being in the position of "eternal refugee". By choosing to die in his freedom developed during Jeon Bong-joon's trial, he also completes the people's spirit of revolution. In the case of simultaneous exploitation in East and West, the form of oppression is the withdrawal of capital from domination and power, and a new alternative to this is the philosophical context that allows the establishment of a new paradigm with "man is the greatest capital".

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.8
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• pp.610-617
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• 2019

The urban-rural complex area in Korea has a distinctive spatial structure where the urban area and rural area coexist. Therefore, in order to cope with the over-depopulation in the rural region of the urban-rural complex area, it is necessary to explore various policies that can prevent the existing residents from leaving, and in fact support them to remain where they currently reside. In this context, this current study analyzed the factors affecting the existing residents' continuous intention to remain by employing the '2017 Chuncheon City Social Survey' as a countermeasure for the over-depopulation of the rural region in the urban-rural complex area. Especially, since a regional identity is determined endogenously, this study used a simultaneous bivariate ordered probit model with giving consideration to the endogenous relationship between a regional identity and a regional residents' intentions. As a result, it was found on analysis that the regional residential intention was higher as the regional identity was stronger. Furthermore, the regional identity was stronger as a householders' age and residence period were longer, and also as the residents were satisfied with their work leisure and life residence balance. It was also found that the residents' intention was higher as the residents' satisfaction with the local medical service and their work was increased. Thus, supporting policy is needed that can provide appropriate quality-of-life services in a timely manner, but only after identifying the demand for these services by the rural residents in the urban-rural complex area.

• Journal of the Korean Institute of Gas
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• v.23 no.4
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• pp.1-9
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• 2019

Large-scale industrial boilers operating at high temperature and high pressure, have a large amount of water, and a large amount of energy is released at the time of explosion. Currently, most industrial boilers use gas fuel such as LNG and LPG, etc. and fuel exists in the same space as equipment, so there is a high possibility of secondary damage such as fire or explosion in the event of a boiler accident. Both special care and management are required to operate the very dangerous equipment that causes casualty 2.51 per accident. For boilers of a certain size or more, the Korea Energy Agency conducts inspections in accordance with the Energy Usage Rationalization Act, KS, and public notice of the Ministry of Industry, Trade and Resources. In this research, based on the results of the inspection, the hazard factorss are configured, and a questionnaire is conducted to the inspector, the equipment manager, the maintenance person, and the person in charge of the manufacturer. We analyzed the results by using AHP (Analytic Hierarchy Process). As a result of analysis, generally recognized hazard factorss are not good management, measurement failure, specification failure, water leak, leak analysis, but connection, welding, scale, and corrosion, etc. are relatively less important. It is judged that the adverse factors that are recognized to be highly important among all groups and careers are already well managed, but less important and adverse factors should be well managed to ensure that the safe usage of the boiler.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.1
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• pp.19-26
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• 2019

The masonry infill walls are one of the most popular components that are used for dividing and arranging spaces in building construction. In spite of the fact that the masonry infills have many advantages, the system needs to be used with caution when the earthquake load is to be considered. The infills tend to develop diagonal compression struts during earthquake and increase the demand in surrounding RC frames. If there are openings in the infill walls, the loading path gets even complicated and the engineering judgements are required for designing the system. In this study, a masonry infill system was investigated through finite element analysis (FEA) and the results were compared with the current design standard, ASCE 41. It is noted that the equivalent width of the compression strut estimated by ASCE 41 could be 32% less than that using detailed FEA. The global load resisting capacity was also estimated by 28% less when ASCE 41 was used compare to the FEA case. Rather than using expensive FEA, the adapting ASCE 41 for the analysis and design of the masonry infills with openings would provide a good estimation by about 25% conservatively.