• Journal of the Korean Chemical Society
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• v.54 no.1
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• pp.150-157
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• 2010

In this study, we investigated the differences of mapping understanding and the types of mapping errors by the levels of students' cognitive/affective variables and the relationships between mapping understanding and these variables in learning 'concentration and reaction rate' with analogy. After administering the tests regarding logical thinking ability, visual imagery ability, analogical reasoning ability, self efficacy, and need for cognition as pretests, students learned with analogy. Then, students' familiarity and mapping understanding were examined. Analyses of the results revealed that the scores of the mapping understanding for the students with higher levels of all cognitive/affective variables except visual imagery ability and familiarity were significantly higher than those for the students with lower levels. The differences in the types of the mapping errors such as overmapping, failure to map, impossible mapping, artificial mapping, mismapping, rash mapping, and retention of a base feature were also found by the levels of students' cognitive and affective variables. The scores of students' mapping understanding were positively correlated with those of all cognitive and affective variables. The results of multiple regression analysis indicated that students' science achievement, logical thinking ability, and familiarity were significant predictors of mapping understanding. Educational implications of these findings are discussed.

• Korean Journal of Environmental Agriculture
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• v.38 no.4
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• pp.262-268
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• 2019

BACKGROUND: To investigate mineralization characteristics of organic resources in the soil, five materials (rice straw, cow manure sawdust compost, microorganism compost, mixed oil-cake, and amino acid fertilizer) were treated according to the nitrogen content, and an indoor incubation experiment was conducted for 128 days. The results of this analysis were applied to determine the nitrogen mineralization pattern of these organic resources. METHODS AND RESULTS: During the constant temperature incubation period, the nitrogen net mineralization rate of the organic resources was the highest in the amino acid fertilizer with the highest nitrogen content, and the lowest in the rice straw with the lowest nitrogen content. A positive correlation (0.96) was observed between the potential nitrogen mineralization rate and total nitrogen content. The mineralization rate constant, k, was negatively correlated with the organic matter (-0.96) and carbon content (-0.97). The nitrogen mineralization rate during the first cropping season, as estimated by the model, was 6.6%, 11.6%, 30.9%, 70.7%, and 81.0% for the rice straw, the cow manure sawdust compost, the microorganism compost, the mixed oil-cake, and the amino acid fertilizer, respectively. CONCLUSION: The nitrogen mineralization rate varies depending on the type of organic resources or the nitrogen content; thus, it can be used as an index for determining the nitrogen supply characteristics of the organic resource. Organic resources such as compost with low nitrogen content or those undergoing fermentation contain organic nitrogen. Organic nitrogen is stabilized during the composting process. Therefore, as the nitrogen mineralization rate of these resources is lower than that of non-fermented organic resources, it is desirable to use the fermented organic materials only to improve soil physical properties rather than to supply nutrients for the required amount of fertilizer.

• Journal of the Korean Association of Geographic Information Studies
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• v.8 no.2
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• pp.1-9
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• 2005

This study was performed to analyze time series landuse pattern of urban areas and the change of the areas by using remotely sensed multiple sensors. The results were as follows. First, according to the result of time series analysis, most agricultural land has been changed into built-up areas by development work such as the land development or land readjustment project, arrangement of science parks or military facilities, and location of public establishment like government buildings. Second, if the expansion of built-up areas maintains the present scale and speed, it seems that a lot of parts of land would be changed into built-up areas, especially centering around agricultural land, so it is necessary to establish the plan for urban space. Third, I have synthetically collected the data of the project of urban development and systematically monitored the process of in expansion the built-up areas up to now (from the past). I hereby could lay the foundation that makes us scientifically forecast the direction of expansion in the built-up areas by the urban development in the future.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.21 no.2
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• pp.203-210
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• 1976

To abtain basic information in process developing cold tolerance rice variety, used 8 varieties which are the close crossing and the remote crossing in order to clarify how is being the differences of low temperature injury in same variety and the varietal difference at each growth stage under the low temperature treatment, 18$^{\circ}C$-12$^{\circ}C$ (day-night), and to establish the effective testing method for low temperature injury in rice plant. In this experiment, the varietal ifferences of low temperature injury were significant in rice plant, and found out that low temperature injury at the each growth stage from sowing to heading in same variety was not horizontal.

• Journal of the Korea Concrete Institute
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• v.27 no.4
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• pp.411-418
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• 2015

This paper investigates the effects of fiber volume fraction and panel thickness on face damage characteristics of steel fiber-reinforced concrete (SFRC) under high-velocity globular projectile impact. The target specimens were prepared with $200{\times}200mm$ prismatic panels with thickness of 30 or 50 mm. All panels were subjected to the impact of a steel projectile with a diameter of 20 mm and velocity of 350 m/s. Specifically, this paper explores the correlation between mechanical properties and face damage characteristics of SFRC panels with different fiber volume fraction and panel thickness. The mechanical properties of SFRC considered in this study included compressive strength, modulus of rupture, and toughness. Test results indicated that the addition of steel fiber significantly improve the impact resistance of conventional concrete panel. The front face damage of SFRC panels decreased with increasing the compressive toughness and rear face damage decreased as the modulus of rupture and flexural toughness increased. To evaluate the damage response of SFRC panels under high-velocity impact, finite element analysis conducted using ABAQUS/Explicit commercial program. The predicted face damage of SFRC panels based on simulation shows well agreement with the experimental result in similar failure mode.

• Journal of the Korean GEO-environmental Society
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• v.1 no.1
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• pp.5-12
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• 2000

Mudstone, found Du-Ho Dong and around there in Po-Hang, is used as construction material. When it is exposed to the air and contacts with water, the strength is decreased rapidly and then it causes a lot of problems. In the field, clay soils with $K_o$ condition have anisotropic characteristics which behave differently according to the change of principal stress direction. In this study, $K_o$ consolidation is performed to make the completely weathered mudstone under the same conditions of construction place. Then, the triaxial compression test is performed at different shear velocity and anisotropy by sampling degree and the stress - strain behavior is shown the strain softening behavior. The stress - strain relationship from triaxial compression test is compared with the prediction value of Cam-clay model. From the results of tests, $K_o$ value decreases with the increase of sampling degree. Generally the behavior of $K_o$ consolidated specimen shows work-softening characteristic. The trend of behaviour of the measured is nearly to same to the predicted by Cam-clay model. But the measured value of deviator stress is very higher than the predicted. Therefore, Cam-clay model was not appropriate to the completely weathered mudstone consolidated with $K_o$ condition in Pohang region.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.6
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• pp.515-519
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• 2010

Introduction: Bone defects in the jaw are frequently observed after odontogenic cyst enucleation. The success of bone healing appears to be related to the size of the bone defect, the anatomical location, the patient's age and other parameters. The use of bone grafting material is dependent on the operator's preference. No evidence-based definite treatment protocol has been established. This study evaluated the effect of a bone graft into the defect after odontogenic cyst enucleation. Materials and Methods: A total of 55 patients, who had been treated for an odontogenic cyst with cyst enucleation from 2000 to 2009 at the department of Oral and Maxillofacial Surgery, Samsung Medical Center, were included in this study. Patients who were followed-up for more than 1 year were included. Two groups were defined according to the bone graft (with or without a bone graft) after cyst enucleation. The differences in the healing periods and patterns of bone healing were compared clinically and radiologically. The postoperative 1 year radiographs were analyzed for bone healing and density. Statistical analysis was performed using a Pearson chi square test and Wilcoxon rank-sum test. Results: More infection signs were observed in the bone graft group than in the other group, but there was no statistically significant difference. Radiographically, there was also no significant difference in the size of the radiolucent lesions between the two groups. Conclusion: There was no significant difference in healing between the groups with a bone graft and without bone graft after cyst enucleation.

• Journal of Korean Society of Forest Science
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• v.45 no.1
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• pp.37-45
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• 1979

The purpose of the study was to define the labor change in the moutainous villages, So this study analyzed the mass dram of the population from the mountainous villages created by the unequal development between the first and second under the high economic development and the large difference in the income between city and rural area. The content of the study was (1) the foundation of the production in the survey area (2) labor change in the mountainous villages (3) the supply and the demand of the labor in this area. The date were collected from 118 household of 2 villages (one with a high level of brest product, and the other with a low level of forest products) in Cheon-nam Province through a questionarie. The results of the study were as follows. 1. The mass drain in the mountainous villages started in the middle of 1970's, and the rate of drain has been very rapid and accelerated. 2. The drain of the mountainous village with a low level of forest products is more than that of the mountainous village with a high level of forest products. 3. In the mountainous village with high level of forest products, the specialization in the farmer class has begun and the farmers with a side job are now increasing. 4. Generally the major drain consisted of the young class (16-30 age), and consequently it caused a change in the composition of labor power into old age and women. 5. The character of the forest labor market is how changing from closed to open.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.2
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• pp.260-267
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• 2015

We investigated the applicability of polyethylene glycol (PEG) as a plasticizer in enteric-coated soft capsules based on determination of quality characteristics according to molecular weight and concentration of enteric-coating PEG solution. There was no difference according to molecular weight of PEG, whereas a low PEG concentration in the enteric-coating solution was associated with higher whiteness index and slower disintegration time in pH 6.8 media. Brittleness was observed in the coating film at seam areas in 5% PEG enteric-coating solution after 2 weeks of storage at room temperature. The enteric-coating properties of PEG were compared with those of acetylated monoglyceride (AMG) and triacetin, which are enteric-coating plasticizers. Enteric-coated soft capsule containing PEG as a plasticizer showed a lower whiteness index and faster dissolution profile than AMG and triacetin. Moreover, enteric-coated soft capsule containing AMG and triacetin as plasticizers showed coating film brittleness at seam areas after 2 months of accelerated storage [$40^{\circ}C$, relative humidity (RH) 75%] but no difference at room temperature storage ($25^{\circ}C$, RH 60%). The present study suggests that concentration of PEG is important to determine enteric-coating quality, regardless of the molecular weight of PEG. In conclusion, PEG has potential as a plasticizer due to its transparency and storage stability in enteric-coated soft capsules.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.3
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• pp.415-420
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• 2013

A method for coating rice with a novel substance, SHC [soybean hydrolysate with Cyclo Histidine-Proline (CHP)], was developed to produce functional rice for food production. The dip coating and spray coating method was tested to reduce the loss of functionality during the manufacturing of enriched rice. The dip coating method showed a very low absorption rate ($0.079min^{-1}$) of the functional substance compared to control ($0.150min^{-1}$), while the spray-coating method with protective coating materials [a methyl cellulose solution (l%, w/v) containing 5% (w/v) of the SHC] showed relatively adequate absorption characteristics. A light yellowish stain was observed in the rice samples processed by the spray-coating method (b value; surface1 0.69, flour 4.91) compared to raw rice (b value; surface 9.67, flour 4.86). The microscopic appearance of whole kernels and longitudinal sections revealed that cracks formed in all rice samples, regardless of the coating method. In conclusion, spray coating is a potential method for producing SHC-fortified rice with excellent physical characteristics.