• Journal of The Korean Association For Science Education
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• v.21 no.4
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• pp.697-709
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• 2001

Researchers on conceptual change have been proposed that confronting a cognitive conflict situation would be important for a student to change his/her preexisting conception. There have been reported that there are three different methods of producing a cognitive conflict situation; the first is logical argument(LC), the second is demonstration of an actual phenomenon(DC), and the third is kinesthetic conflict which is a kind of physical experience(EC). In this study, the researcher tried to find out the differences in the conceptual changes by the three different conflict situations. Seventy two high school students were chosen in a high school in Kyungkido, Korea. The students were tested four times; pretest, posttest, one week delayed posttest, and one month delayed posttest. Six different test situations on mechanics were developed for this study. Test item for each situation was developed. Each item consisted of a multiple choice question and explanation of the choice. The result showed a clear differences among the three conflict groups. In general, kinesthetic conflict which is a kind of physical experience(EC) was proved to be the most efficient strategy for the conceptual change; however, logical argument(LC) seemed to be the least efficient. However, the effectiveness was not uniform from situation to situation. Results of some items showed that even the LC was quite good for the conceptual change. Therefore, it seems to be important to develope appropriate method for the target concept.

• Journal of the Korean Geographical Society
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• v.39 no.1
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• pp.102-115
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• 2004

As a household's residential location is closely related to its workplace and place of education, the urban exodus of city dwellers changes their ways of commuting to workplace and attending school. This paper examines the influence of urban exodus on the change of a way of life through relations between residential location and modes of commuting. Despite moving to the countryside, exurban migrants still want to experience rural health without abandoning the city lifestyle. However, they are faced with various difficulties in commuting to workplace and attending school, because suburban and exurban areas have poor accessibility to the central city. In order to overcome these problems, most of them choose "the residential segmentation of the family" through which the head of the family commutes to the city from his or her family home in exurban areas and children go to school from their second home in the central city, or try "to link commuting to workplace with attending school".

• The Journal of the Korea Contents Association
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• v.17 no.12
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• pp.386-398
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• 2017

The purpose of this study was to examine what kind of changes adolescents experienced in the process of returning from the school dropout. For this purpose, 'Qualitative Meta-Analysis' was conducted for seven papers of this area, which was published in Korean journals as a method. 'Qualitative Meta-Analysis' is a method of presenting new interpretations by synthesizing qualitative studies on the same topic. In this study, the qualitative research on the process of returning from the school dropout was selected. The final articles selected for the analysis were seven articles published in domestic journals. The results obtained by comparing and analyzing the selected individual papers were as follows. For adolescents, a series of the process of returning from school dropout was 'self-growth through introspection and support.' In this process, there were five stages of change: abandonment, drifting, self-awareness, decisive action, and struggles. Relevant factors that led to this change were self-perception, the awareness of a reality, resources and support. Based on these results, the characteristics of each step were explained and discussed. Finally, the implications and limitations of the study were clarified and the follow-up study was proposed for more detailed examination.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.262.1-262.1
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• 2014

Lipid peroxidation induces functional deterioration of cell membrane and induces cell death in extreme cases. These phenomena are known to be related generally to the change of physical properties of lipid membrane such as decreased lipid order or increased water penetration. Even though the electric property of lipid membrane is important, there has been no report about the change of electric properties after lipid peroxidation. Herein, we demonstrate the molecular energy band change in red blood cell membrane through peroxidation by air-based atmospheric pressure DBD plasma treatment. Ion-induced secondary electron emission coefficient (${\gamma}$ value) was measured by using home-made gamma-focused ion beam (${\gamma}$-FIB) system and electron energy band was calculated based on the quantum mechanical Auger neutralization theory. The oxidized lipids showed higher gamma values and lower electron work functions, which implies the change of surface charging or electrical conductance. This result suggests that modified electrical properties should play a role in cell signaling under oxidative stress.

• Restorative Dentistry and Endodontics
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• v.28 no.4
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• pp.326-333
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• 2003

Ormocer has organic-inorganic compound polymers. One of advantages of ormocer is reduced polymerization shrinkage. The purpose of this study was to compare the amount of contraction shrinkage of composite resins and ormocers. Additionally, the time of each material when there is no further change of contraction shrinkage was analysed. Four brands of composite resins (P-60. Surefil, Z-250 and Denfil) and two brands of ormocers (Definite and Admira) were used. 20 seconds, 40 seconds and 60 seconds of curing times were given. Contraction shrinkage of them were measured using a linometer for 80 seconds. The effect of material and curing time to contraction shrinkage at the time of 80 seconds was analysed by two-way ANOVA. The effect of time to contraction shrinkage was analysed by one-way ANOVA and the time when there was no further change of the contraction shrinkage was analysed. The results are as follows: 1. P-60, Definite, Z-250 and Denfil had no further change of contraction shrinkage from the time of 20 seconds, and Surefil and Admira had no further change of contraction shrinkage from the time of 10 seconds. 2. Statistical analysis revealed volumetric shrinkage varied among material (p<0,05). No significant difference of contraction shrinkage among different curing times was found, and there was no effect of interaction between materials and curing times to contraction shrinkage. 3. Definite and Admira showed the statistically same contraction shrinkage with those of Z-250 and P-60. which is higher than that of Surefil and lower than that of Denfil (p<0.05).

• Journal of the korean academy of Pediatric Dentistry
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• v.25 no.3
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• pp.583-597
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• 1998

The purpose of this study was to evaluate temperature change occurred in enamel, dentin and pulp due to the heat from cavity prepration with laser. We made three models had different cavity depth: cavity depth of model A was 3.52mm, model B was 2.32mm, model C was 1.16mm. We irradiated cavity base with thermal capacity of $30J,100J,300J/cm^2s$ during few seconds and studied the change of temperature in tooth during 10 seconds, and estimated change of thermal capacity by different irradiated site and exposure time. At $300J/cm^2$ irradiation for 2 seconds, the temperature of irradiated surface was elevated fast according to irradiated thermal energy during 1 second. In proportion to continuous exposure time, temperature elevated slowly. The surface temperature was $1370^{\circ}C$. After discontinue of thermal irradiation, the heat of irradiated surface was diffused in dentin and pulp and the greatest temperature was made. The greatest temperature was disappeared within 10 seconds The greatest temperature of the inner part of model brought about very severe change by different depth. Temperature in pulp was raised by the greater irradiated energy density and exposure time.

• Journal of Climate Change Research
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• v.8 no.3
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• pp.231-237
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• 2017

In this study, the $N_2O$ emission factor of the facility was developed by measuring the kiln type pyrolysis melting facility. This used PAS (Photoacoustic Spectroscopy) method and measured the $N_2O$ emission concentration. From March 2016 to April 2016, it was measured over a total of two times and $N_2O$ concentrations were measured continuously for 24 hours using a 24 hour continuous measuring instrument (LSE-4405). The measured $N_2O$ emission concentration of the pyrolysis melting facility was 0.263 ppm on average and the emission concentration distribution in the range of 0.013~0.733 ppm was obtained. Therefore, the $N_2O$ emission factor of the kiln-type pyrolysis melting facility was estimated to be $0.829gN_2O/ton$-Waste. As a result of comparing the $N_2O$ emission factor of the thermal kiln type pyrolysis melting facility and the previous study, previous studies were about 18 times higher. It is estimated that this is due to the difference of furnace temperature, oxygen concentration and denitrification facilities. It is considered that the study of the emission factor of pyrolysis melting facility is an important factor in improving the credibility of greenhouse gas inventory in waste incineration sector.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.426-429
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• 2007

One of the widely used applications of remote sensing studies is environmental change detection and biodiversity conservation. The study area Hustai Mountain is situated in the transition zone between the Siberian taiga forest and Central Mongolian arid steppe. Hustai National Park carries out one of several reintroduction programs of takhi (wild horse or Equus ferus przewalskii) from various zoos in the world and it represents one of a few textbook examples of successful reintroduction of an animal extinct in the wild. In this paper we describe the results of an analysis on the change of remaining forest area over the 7-year period since Hustai Mountain was designated as a protected area for reintroduction to wild horses. Today the forested area covers approximately 5% of the Hustai National Park, mostly the north-facing slopes above 1400 m altitude. Birch (Betula platyphylla) and aspen (Populus tremula) trees are predominant in the forest. We used Landsat ETM+ images from two different years and multi temporal MODIS NDVI data. Land types were determined by supervised classification methods (Maximum Likelihood algorithm) verified with ground-truthing data and the Land Change Modeler (LCM) which was developed by Clark Labs. Forested area was classified into three different land types, namely the forest land, mountain meadow and mountain steppe. The study results illustrate that the remaining birch forest has rapidly changed to fragmented forest land and to open areas. Underlying causes for such a rapid change during the 15-year period may be manifold. However, the responsible factors appear to be the drying off and outbreak of forest pest species (such as gypsy moth or Lymantria dispar) in the area.

• Journal of the Korean GEO-environmental Society
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• v.15 no.6
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• pp.31-39
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• 2014

The objective of this study is to suggest the proper sediment transport equation and short and long-term bed change for planning and implementing the river management in Korea. To analyze total sediment discharge and short and long-term bed change, existing sediment transport equations, HEC-RAS 4.1 and CCHE2D numerical models were applied in urban and mountainous rivers. The results of this study are as followings; Firstly, the modified Einstein equation showed the most appropriate result for the estimation of total sediment discharge in the local rivers. Secondly, The stage-discharge relation curve and the discharge-total sediment discharge relation curve were suggested to examine the characteristics of river bed change. Finally, it is founded that river bed change of mountainous river has occurred greater than that of the urban river, and the river bed of urban river now tends to be stabilized on the whole.

• Advances in Energy Research
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• v.8 no.1
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• pp.73-93
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• 2022

Focus on climate change and extreme weather conditions has received considerable attention in recent years. Civil engineers are now focusing on designing buildings that are more eco-friendly in the face of climate change. This paper describes the research conducted to assess the impact of future climate change on energy usage and carbon emissions in a typical supermarket at multiple locations across the UK. Locations that were included in the study were London, Manchester, and Southampton. These three cities were compared against their building performance based on their respective climatic conditions. Based on the UK Climatic Projections (UKCP09), a series of energy modelling simulations which were provided by the Chartered Institute of Building Service Engineers (CIBSE) were conducted on future weather years for this investigation. This investigation ascertains and quantifies the annual energy consumption, carbon emissions, cooling, and heating demand of the selected supermarkets at the three locations under various climatic projections and emission scenarios, which further validates annual temperature rise as a result of climatic variation. The data showed a trend of increasing variations across the UK as one moves southwards, with London and Southampton at the higher side of the spectrum followed by Manchester which has the least variability amongst these three cities. This is the first study which investigates impact of the climate change on the UK supermarkets across different regions by using the real case scenarios.