• Tunnel and Underground Space
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• v.33 no.6
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• pp.574-593
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• 2023

In this study, the effectiveness and applicability of a newly designed Compact CNS shear box for conducting direct shear tests on jointed rock specimens were investigated. CNS joint shear tests were conducted on jointed rocks with Artificially generated roughness while varying the fracture surface roughness coefficient and initial normal stress conditions. In addition, displacement data were validated by Digital image correlation analysis, fracture patterns were observed, and comparative analysis was conducted with previously studied shear behavior prediction models. Furthermore, the accuracy of the displacement data was confirmed through DIC analysis, the fracture patterns were observed, and the shear properties obtained from the tests were compared with existing models that predict shear behavior. The findings exhibited a strong correlation with specific established empirical models for predicting shear behavior. Furthermore, the potential linkage between the characteristics of shear behavior and fracture patterns was deliberated. In conclusion, the CNS shear box was shown to be applicable and effective in providing data on the shear characteristics of the joint.

• Journal of the Korean Institute of Gas
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• v.27 no.4
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• pp.19-26
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• 2023

Earthquakes are one of the most important disasters affecting underground structures. Urban gas underground pipes may cause safety problems of structures in the event of an earthquake. Since Korea began digital observation, the number of earthquakes has been steadily increasing. The seismic design standard for urban gas pipes was established in 2008, but it is difficult to estimate the impact of pipes in the event of an earthquake based on the installation of pipes. In this study, structural analysis was performed on PE (polyethylene pipe) pipes and PLP (polyethylene coated steel pipe) pipes, which are mainly used as buried pipes in Korea, according to environmental and pipe variables in the event of an earthquake. This study sought to find the variables of the most vulnerable buried pipe by modeling pipes through Computer Aided Engineering (CAE) and generating displacement on the ground. Through this study, it was confirmed that the larger the elastic modulus of the soil, the deeper the buried depth, the smaller the tube diameter, and the higher the pressure, the more PLP pipes are affected by earthquakes than PE. Based on these results, the vulnerable points of buried urban gas pipes are inferred and used for special inspections of buried pipes in the event of an earthquake.

• Journal of the Korean Association of Geographic Information Studies
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• v.27 no.2
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• pp.1-18
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• 2024

This study aimed to identify the optimal street tree planting method to improve the summer thermal environment in Seoul, Republic of Korea. The effects of road direction and street tree planting patterns on urban thermal environments using ENVI-met simulations were analyzed. The 68 scenarios were analyzed based on four road directions and 17 planting patterns. The results showed that tree planting had a reducing air temperature, mean radiant temperature, human thermal sensation (PET and UTCI). The most effective planting pattern among all scenarios was low tree height (6m), wide crown width (9m), high leaf area index (3.0), and narrow planting interval (8m). The largest improvement in the thermal environment was the northern sidewalk of the east-west road. Since this study used computer simulations, the difference from real urban spaces should be considered, and further research is needed through field measurement and consideration of more variables.

• Journal of the Korean Magnetics Society
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• v.14 no.2
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• pp.76-82
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• 2004

Crystallographic and magnetic properties for Brownmillerite-type oxides $Ca_{1-x}$Sr$_{x}$FeO$_{2.5}$ (x = 0, 0.3, 0.5, 0.7, 1.0) were investigated using x-ray diffraction (XRD) and Mossbauer spectroscopy. Polycrystalline samples were prepared by conventional solid-state reaction method. Information on exact crystalline structures, lattice parameters, bond lengths and bond angles were obtained by refining their XRD profiles using a Rietveld method. The crystal structures were found to be all orthorhombic with space group Icmm (x = 0, 0.3) and Icmm (x = 0.5, 0.7, 1.0) The lattice parameters increased monotonically with increasing Sr concentration. Both the tetrahedral and the octahedral sites were considerably distorted and elongated along b-axis. While bond lengths and bond angles O-Fe-O tend to increase minutely with the increase of Sr content, bond angles Fe-O-Fe decreased accordingly. The Mossbauer spectra showed two sets of sharp sextets originating from ferric ions occupying the tetrahedral and the octahedral sites under the magnetic transition temperature T$_{N}$. Regardless of the compositions x, the electric quadrupole splittings were -0.3 mm/s and 0.4 mm/s for the octahedral and the tetrahedral site, respectively. Above T$_{N}$, the Mossbauer spectra showed the paramagnetic doublets whose electric quadrupole splittings were about 1.6 mm/s, irrespective of compositions x. T$_{N}$ was found to decrease monotonically with the increase of Sr concentration. Ratios of absorption area for the two sites were almost 1:1 up to as high as 0.95 T$_{N}$ for all x. The result of the Debye temperature indicated that the inter-atomic binding force for the Fe atoms in the tetrahedral site was stronger than that for the octahedral site.hedral site.

• Tuberculosis and Respiratory Diseases
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• v.57 no.4
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• pp.351-357
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• 2004

Background : Paclitaxel is highly beneficial anticancer drug for the treatment of non-small cell lung cancer and has shown remarkable radiosensitizing effect in vitro. We evaluated whether concurrent chemoradiation therapy with weekly paclitaxel (60 $mg/m^2$) could be tolerated and effective in the treatment of locally advanced non-small cell lung cancer (NSCLC). Methods : Twenty-two stage III (IIIA:6, IIIB:16) NSCLC patients were treated with weekly administration of paclitaxel (60 $mg/m^2$) on days 1, 8, 15, 22, 29, and 36 in addition to concurrent radiation therapy of 54 Gy. After the initial phase of concurrent chemoradiation, patients received additional two cycles of consolidation chemotherapy with paclitaxel (175 $mg/m^2$)/cisplatin (75 $mg/m^2$) or paclitaxel (175 $mg/m^2$)/carboplatin (6AUC) every 3 weeks. Results : Overall response rate was 81.8% (18/22) with 9.1% (2/22) of complete response and 72.7% (16/22) of partial response rate. Two patients (9.1%) died of chemoradiation-induced pneumonitis after completion of therapy. In total, grade 3 toxicities included pneumonitis (22.7%), esophagitis (22.7%), neuropathy (13.6%), and neutropenia (13.6%). The median survival time was 15 months and 2-year overall survival were 31.8%. Conclusion : Concurrent chemoradiation therapy with weekly paclitaxel in locally advanced NSCLC showed good local response, but survival rate was not completely satisfactory due to potentially fatal chemoradiation-induced pneumonitis.

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.2
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• pp.163-169
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• 2014

Purpose: This study is for compared the change of corneal refractive power before and after wearing of rigid gas permeable contact lense with diagnostic method which is 1 D flatter than alignment fitting on right eye and alignment fitting on left eye for 2 months and investigate the preference. Methods: Twenty middle school and high school students (40 eyes) who had never worn a contact lense before for no corneal topographical change, no ocular disease, no experience of ophthalmic surgery and have normal tear amount were selected for this study and corneal refractive power were examined before wearing rigid gas permeable contact lense and adaptation status and corneal examination were performed after 10 days of wearing and after cheking up the continuation of wearing, all candidate wear contact lens 8 hours per day for 2 month and corneal refractive power were compared. Results: After 2 months of wearing with 1 D flatter than the alignment fitting on right eyes, there was significant difference in the central corneal refractive power was $43.84{\pm}1.33D$, flat K power was $43.05{\pm}1.29D$, and steep K power was $44.61{\pm}1.42D$ decreased than before wearing (p<0.001, 0.001, 0.047). The e-value of the principal meridians also shows statistically significant difference (p=0.037, 0.015). After 2 months of wearing with alignment fitting on left eyes, the central corneal refractive power was $44.40{\pm}1.26D$, flat K power was $43.57{\pm}1.23D$. and flat K e-value was $0.58{\pm}0.05$ which showed no statistically significant difference (p = 0.769, 0.614, 0.181). But steep K power was $45.25{\pm}1.36$, and steep K e-value was $0.45{\pm}0.18$ which shows statistically significant difference (p=0.018, 0.027). Conclusions: Consider the comfort, clear vision, dryness for preference fitting investment, 6 students (30%) prefer right eye which is 1 D flatter fitting, 14 students (70%) prefer left eye which is alignment fitting. For rigid gas permeable fitting needed for accurate examination and should prescribe the alignment fitting which is suitable for each cornea.

• Journal of Korean Home Economics Education Association
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• v.26 no.4
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• pp.1-19
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• 2014

The purpose of this study was to investigate perception of snack purchasing behaviors and labeling of foods and nutrition of the middle school students. The survey was conducted from 424 students who are boys and girls of middle school in Naju. Data were analyzed by a SPSS program. According to the survey, snack purchase place had a significant difference between gender(p<.05), and all of the boys and girls responded at a high rate that it's convenience store. Snack eating frequency had a significant difference between boys and girls(p<.05). Boys responded that they ate 1~2 times per a week the most, and girls responded that they ate 1~2 times per a month the most. As for snack purchasing behaviors, depending on gender, that of boys was 2.76 in average and that of girls was 2.87, lower than middle. The reason why students didn't check up food labeling, depending on gender and all of the boys and girls responded 'Expiration date' was first confirmed. As for the understanding of food expression, depending on snack expenses, the reason why food expression contents were hard showed a significant difference, depending on snack expenses(p<.05). As for the understanding of food expression, depending on snack purchase attitude, the students showed a significant difference, depending on snack purchase attitude(p<.001), and the lower the snack purchase attitude was, the less the students checked up snack expression. The reason why students checked up nutrition labeling a significant difference, depending on gender, snack expense and snack purchase attitude(p<.001). 'Weight management' was the highest. The recognition in the necessity of nutrition expression(p<.001) and the necessity of food/ nutrition education and publicity(p<.01) showed significant difference.

• Tuberculosis and Respiratory Diseases
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• v.61 no.4
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• pp.366-373
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• 2006

Background: Paraquat is extremely toxic chemical material, which generates reactive oxygen species (ROS), causing multiple organ failure. In particular, paraquat leads to irreversible progressive pulmonary fibrosis. Exaggerated cell deaths exceeding the normal repair of type II pneumocytes leads to mesenchymal cells proliferation and fibrosis. This study examined the followings; i) whether or not paraquat induces cell death in lung epithelial cells; ii) whether or not paraquat-induced cell deaths are apoptosis or necrosis; and iii) the effects of N-acetylcysteine, dexamethasone, and bcl-2 on paraquat-induced cell deaths. Methods: A549 and BEAS-2B lung epithelial cell lines were used. The cell viability and apoptosis were evalluated using a MTT assay, Annexin V staining was monitored by fluorescence microscopy, The level of bcl-2 inhibition was examined by establishing stable A549 pcDNA3-bcl-2 cell lines throung the transfection of pcDNA3-bcl-2 with the mock. Results: Paraquat decreased the cell viability in A549 and BEAS-2B cells in a dose and time dependent manner. The Annexin V assay showed that apoptosis was the type of paraquat-induced cell death. Paraquat-induced cell deaths was significantly inhibited by N-acetylcysteine, dexamethasone, and bcl-2 overexpression. The cell viability of A549 cells treated with N-acetylcysteine, and dexamethasone on the paraquat-induced cell deaths were increased significantly by 10 ~ 20%, particularly at high doses. In addition, the cell viability of A549 pcDNA3-bcl-2 cells overexpressing bcl-2 was significantly higher than the untransfected A549 cells. Conclusion: Paraquat induces apoptotic cell deaths in lung epithelial cells in a dose and time dependent manner. The paraquat-induced apoptosis of lung epithelial cells might occur through the mitochondrial pathway.

• Journal of Science Education
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• v.37 no.3
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• pp.525-537
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• 2013

The purpose of this study was to investigate science integrated process skill of the students in science education center for the gifted. In order to do this, 'free-response test for the assessment of science process skills' developed by Yu-Hyang Kim(2013) was administered to 102 students(15 in elementary school science class, 58 in middle school science class I, and 29 in middle school science class II) who attend the program of science education center for the gifted in C university. The assessment tool measured 9 skills ; formulating inquiry questions, recognizing variables, formulating hypotheses, designing experiment, transforming data, interpreting data, drawing conclusions, formulating generalizations, and evaluating the designed experiments. As a result, the students in science education center for the gifted had relatively high scores in the area of 'formulating hypotheses' and 'recognizing variables', but they had relatively low scores in the area of 'transforming data', 'interpreting data', and 'evaluating the designed experiments'. The 2 items' percentage of correct answers were below 40% ; one is about a drawing a line graph in 'transforming data', and the other requires finding improvements of the experimental design in 'evaluation'. There was no significant difference between boys' scores and girls's one, and between the scores of students in the field of biology and those of students in the other fields(physics, chemistry, and earth science) in science integrated process skills. And there was significant difference according to the periods receiving the gifted education in 'formulating generalizations'. The teaching and learning has to focus on improving science integrated process skills in the program of science education center for the gifted and teaching and learning materials needs to be developed.

• Journal of The Korean Society of Grassland and Forage Science
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• v.18 no.3
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• pp.171-178
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• 1998

This experiment was conducted to study on forage utility of Diplachne fusca L. which live in reclaimed saline land of midwest region of Korea. The primary experiment was conducted to know on germination characteristics of Diplachne fusca L. according to storage condition after seed harvesting, light, temperature, flooding depth, salinity and soil covering. The results obtained are summarized as follows; 1. The germination percentage, average days to germination, germination rate and coefficient of germination were not different in existence of light, combination with existence of light and storage condition, but those were higher different in storage condition. 2. The germination characteristics were more higher on the condition of alternating temperature than constant temperature, and it was the highest on the condition of alternating temperature with $35/25^{\circ}C$ and constant temperature with $35^{\circ}C$. 3. There were apparently significant in germination percentage, average days to germination, germination rate and coefficient of germination according to flooding depth. The germination characteristics of D. fusca L. were the highest on the wndition of flooding depth with Ocm and did not germinate on the condition of flooding depth more than 3cm. 4. There were apparently significant in germination percentage, average days to germination, germination rate and coefficient of germination according to salinity. Germination characteristics were the highest on the condition of salinity with 0.2%. There was more than 30% of germination percentage on the condition of salinity with 1% SO Diplachne fuaca L. was suitable to cultivate in reclaimed saline land. 5. The germination percentage, average days to germination, germination rate and coefficient of germination were significantly difference between soil covering. So Germination characteristics were the highest on the condition of soil covering with 0.2cm. But they scarcely germinated on the condition of more than 1cm of the soil covering.