• Journal of Korean Home Economics Education Association
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• v.20 no.1
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• pp.137-152
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• 2008

This study examined the organization and operation of home economics curriculum of specialized middle school in the form of regular school among alternative schools and analyzed the perceptions of teachers and students about home economics class. Interviews were conducted with teachers of 6 specialized schools in order to determine the operations and teachers' perceptions of home economics education. Students' perceptions for home economics class were gathered through surveys with students from the 3 (of the original 6) schools that authorized the questionnaire survey. The final analysis utilized 205 student responses. Survey data were analyzed using the SPSS program. The results of the research were as follows: First, home economics education within specialized middle schools was mostly conducted according to the form of the technology-home economics curriculum, which is the national common basic curriculum. Compared to the 7th national curriculum, the class of technology-home economics curriculum in 4 schools occurred 1 hour less each week. Each school incorporated various specialized curricula related to home economics. Second, as for the operation of home economics education in specialized schools, most home economics classes were conducted by teachers who had majored (or minored) in home economics. Moreover, all but 1 school, which used self-made materials, used the national textbook and dealt with the entire content of the textbook. For teaching-learning methods and instructional media, various means were utilized. For evaluation methods, most schools based grades on paper-and-pencil tests(50-60%) and performance tests(40-50%). Third, among teachers' perceptions of home economics education, the meaning of home economics education was focused on practical help and the pursuit of home happiness; the purpose was to realize the happiness of students and their homes by applying these to actual living, and increase students' ability to see the world. In regards to difficulties in educational operations, most pointed out poor conditions of practice rooms. As for differences from general schools, most teachers mentioned the active communication with students. Fourth, through the home economics class, it was found that students perceived the goal of technology-home economics curricula as lower than average. Among students' perceptions about home economics class, most were negative. Perceptions about goal of technology-home economics curricula and home economics class also showed meaningful differences according to each school. Students of the school, which had more home economics class hours and specialized curricula related to home economics, perceived more positively. Also, students who were more satisfied with school and learned from a teacher who majored in home economics tended to perceive home economics class more positively.

• The Korean Journal of Ecology
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• v.26 no.1
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• pp.39-47
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• 2003

The leaf aqueous extracts from five gymnosperms plant were investigated for allelopathy with five Hibiscus syriacus varieties. The leaf aqueous extract of Pinus rigida had the highest total phenolic compound of 2.21mg/L, whereas the soil under Pinus koraiensis canopy had the highest total phenolic compound of 1.38mg/L. Fourteen phenolic compounds were isolated from five gymnosperm plants by HPLC. Among them, phenolic compounds were the highest in P. rigida (320.56 g/mg) with the primary compound 5-sulfosalicylic acid (312.55 g/mg). The correlation between leaf total phenolic compound and pH was not significant, while the total phenolic compound of the leaf extract changed soil pH. The relative seed germination of H. syriacus varieties showed 25% was threshold concentration. The germination rates of varieties were similar to the control group or showed slight stimulation to treatment of P. koraiensis extract. H. syriacus Cambanha was similar to the control group or showed stimulation in all treated groups. H. syriacus Seohohyang showed stimulation in both root and shoot growth compared to the control group. In other varieties except Seohohyang, shoot growth was similar to the control group, while root growth was stimulated in all treated groups. The extracts of tested gymnosperms showed significantly more stimulation to transplanted Seohohyang seedlings, whereas others were similar to control or inhibited in the greenhouse. The dry weight of Seohohyang was greater in all treated groups than the control group, while other varieties were inhibited. All gymnosperm extracts stimulated the chlorophyll contents of Seohohyang and H. syriacus Koyoro but other varieties were not significantly affected. Accordingly, it is suggested that Seohohyang seems the most desirable when planted within these five gymnosperms.

• Korean Chemical Engineering Research
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• v.54 no.2
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• pp.213-222
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• 2016

Solubility data of hydrogen sulfide ($H_2S$) and methane ($CH_4$) in two kinds of ionic liquids with the same anion: 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ([emim][TfO]) and 1-butyl-1-methylpyrrolidinium trifluoromethanesulfonate ([bmpyr][TfO]) are presented at pressures up to about 30 MPa and at temperatures between 303 K and 343 K. The gas solubilities in ionic liquids were determined by measuring the bubble point pressures of the gas + ionic liquid mixtures with various compositions at different temperatures using a high-pressure equilibrium apparatus equipped with a variable-volume view cell. The $H_2S$ solubilities in ionic liquid increased with the increase of pressure and decreased with the increase of temperature. On the other hand, the $CH_4$ solubilities in ionic liquid increased significantly with the increase of pressure, but there was little effect of temperature on the $CH_4$ solubility. For the ionic liquds [emim][TfO] and [bmpyr][TfO] with the same anion, the solubility of $H_2S$ as a molality basis was substantially similar, regardless of the temperature and pressure conditions as a molar concentration basis. Comparing the solubilities of $H_2S$ and $CH_4$ in the ionic liquid [emim][TfO], the solubilities of $H_2S$ were much greater than those of $CH_4$. For the same type of ionic liquid, the solubility data of $H_2S$ and $CH_4$ obtained in this study were compared to the solubility data of $CO_2$ from the literature. When compared at the same pressure and temperature conditions, the $CO_2$ solubility was in between the solubility of $H_2S$ and $CH_4$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.9
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• pp.1482-1491
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• 2013

The purpose of this study was to investigate the safety accidents and physical fatigues of school foodservice employees. Out of 300 questionnaires distributed from December 1~20, 2011, 276 responded. After excluding 54 incomplete questionnaires, 222 (usage rate: 74%) were examined in the final analysis. First, our results showed that in terms of safety accidents, most received bruises (92.8%), followed by burns (73.0%), cuts and lacerated wounds (69.4%), sprains (47.7%), falls (42.8%), fractures/dislocations (31.5%) and electric shock (2.7%). Second, we found that the average degree of physical fatigue of school foodservice employees was 3.65 based on the 5-point Likert scale. Specifically, pain in the arms and wrist was rated the highest, at 4.18. Third, results showed that the factors affecting physical fatigue were 'class of school' (P<0.05), 'frequency of meal serving per day' (P<0.05), 'no. of meals served per day' (P<0.001), 'no. of meals per employee' (P<0.05) and 'warm-up exercise before starting work' (P<0.05). This means that foodservice employees serving middle schools, serving meals three times per day, serving more than 1,000 meals per day, and serving more than 111 meals per employee perceive higher levels of physical fatigue. In addition, the physical fatigue of those who perform warm-up exercises before starting work was significantly lower than those who do not perform warm-up exercises before work (P<0.05). In conclusion, the frequently occurring major safety accidents of school foodservice employees were bruises and burns. An increase in workload also leads to the increasing physical fatigue of school foodservice employees. Thus, to lower the physical fatigue of school foodservice employees, school foodservice employees should be encouraged to perform warm-up exercises before staring work and new staffing guidelines for school foodservice employees should be developed.

• Journal of Dental Rehabilitation and Applied Science
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• v.36 no.3
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• pp.183-195
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• 2020

Purpose: The purpose of this study is to compare the flexural strength of CAD/CAM denture base resins with conventional denture base resins based on their thicknesses. Materials and Methods: For the conventional denture base resins, Lucitone 199^® (C-LC) was used. DIOnavi - Denture (P-DO) and DENTCA Denture Base II (P-DC) were taken for the 3D printing denture base resins. For the prepolymerized PMMA resins, Vipi Block Gum (M-VP) and M-IVoBase^® CAD (M-IV) were used. The final dimensions of the specimens were 65.0 mm x 12.7 mm x 1.6 mm / 2.0 mm / 2.5 mm. The 3-point bend test was implemented to measure the flexural strength and flexural modulus. Microscopic evaluation of surface of fractured specimen was conducted by using a scanning electron microscope (SEM). After testing the normality of the data, one-way ANOVA was adopted to evaluate the differences among sample groups with a significance level of P = 0.05. The Tukey HSD test was performed for post hoc analysis. Results: Under the same thicknesses, there are significant differences in flexural strength between CAD/CAM denture base resins and conventional denture base resins except for P-DO and C-LC. M-VP showed higher flexural strength than conventional denture base resins, P-DC and M-IV displayed lower flexural strength than conventional denture base resins. Flexural modulus was highest in M-VP, followed by C-LC, P-DO, P-DC, M-IV, significant differences were found between all materials. In the comparison of flexural strength according to thickness, flexural strength of 2.5 mm was significantly higher than that of 1.6 mm in C-LC. Flexural strength of 2.5 mm and 2.0 mm was significantly higher than that of 1.6 mm in P-DC and M-VP. In M-IV, as the thickness increases, significant increase in flexural strength appeared. SEM analysis illustrates different fracture surfaces of the specimens. Conclusion: The flexural strength of different CAD/CAM denture base resins used in this study varied according to the composition and properties of each material. The flexural strength of CAD/CAM denture base resins was higher than the standard suggested by ISO 20795-1:2013 at a thickness of 1.6 mm or more though the thickness decreased. However, for clinical use of dentures with lower thickness, further researches should be done regarding other properties at lower thickness of denture base resins.

• Sleep Medicine and Psychophysiology
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• v.5 no.1
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• pp.71-79
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• 1998

Objectives : This study was to evaluate sleep patterns and daytime sleepiness resulting from rotating shiftwork. The authors, also, tried to find out the relationship between the severity of daytime sleepiness and personality factors. Methods : The subjects consisted of 41 female rotating shiftwork nurses and the control group consisted of 39 female day timeworkers. All of them completed the Sleep questionnaire of Korea University Sleep Disorder Clinic, the Epworth Sleepiness Scale(ESS), the 16 Personality Factors(16PF), the Beck Depression Inventory(BDI) and the State Trait Anxiety Inventory(STAI). Multiple regression analysis of 16PF of the rotating shiftwork nurses was done to find out possible predictors of the severity of daytime sleepiness. Results : The mean duration of deprived sleep due to rotating shiftwork was $64.26\;{\pm}\;14.54\;min$. The frequency of sleep difficulty($1.24\;{\pm}\;1.17\;day/week$ vs $0.67\;{\pm}\;1.31\;day/week$, p < 0.05), time needed to fall asleep($103.05\;{\pm}\;73.48\;min$. vs $70.00\;{\pm}\;60.08\;min$, p < 0.05), sleep duration when having some difficulties in sleep ($204.25\;{\pm}\;79.90\;min$. vs $280.44\;{\pm}\;111.59\;min$., p < 0.001), recent changes in energy($x^2\;=\;4.16$, p < 0.05), worrying about sleep($x^2\;=\;11.08$, p < 0.05), and taking naps($x^2\;=\;4.98$, p < 0.05) showed significant differences between rotating shiftworkers and normal controls. The ESS socre of shiftworkers ($8.68\;{\pm}\;3.04$) was greater than that of normal controls ($6.86\;{\pm}\;3.04$)(p < 0.01). Personality factors such as C factor($R^2\;=0.283$), I factor($R^2\;=0.358$) and G factor($R^2\;=0.470$) were related with the severity of the daytime sleepiness(p < 0.001). Conclusions : The rotating shiftwork nurses had more difficulties in sleep such as having difficulties in falling asleep and in maintaining sleep, and showed lowered energy, decreased senses of well-being and so on. The rotating shiftwork nurses experienced more severe daytime sleepiness than controls did. Personality factors, such as C factor, I factor, and G factor of 16PF were suggested to be useful for predicting the severity of daytime sleepiness resulting from rotating shiftwork.

• Journal of the Korean Institute of Landscape Architecture
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• v.43 no.4
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• pp.62-74
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• 2015

This study was carried out to provide examples of planting methods for the construction of street green spaces with abundant greenery by analyzing road type, surrounding land use and planting structures in street green spaces on Port Island, Kobe, Japan. Port Island_(total area: 826ha) is a marine cultural city located in Japan's first artificial island with facilities of urban function and port facilities. The study site was designated at 11 plots of $55{\sim}285m^2$ on Port Island, and topography structure styles were divided into four types with mounding style, slope style, slope and flat style, flat style according to the adjacent roads width. The area adjacent to the middle roads with high levels of noise and pollution set up the mounding style, slope style, slope and flat style of multi-layer structures using topographic properties. The area adjacent to small roads focused on a green strip with shrubs on a flat style. Surrounding land-uses include a public institution, housing complex, and a commercial building. The planting concept was a buffer and landspace function in case of the middle road_(lane 4) while the small road_(lane 2) was a landspace function. Planting species were diverse with Liquidambe formosana, Cinnamomum camphora, Sapium sebiferum, Cedrela sinensis, Laeocarpus sylvestris var. ellipticus, Ginkgo biloba, Prunus serrulata var. spontanea, Zelkova serrata, Quercus glauca, Juniperus chinensis, Magnolia kobus, Rhododendron spp., Camellia japonica, Abelia mosanensis, etc. Planting density was 0.02~0.08(0.04) individual/$m^2$ at the canopy layer, 0.02~0.08(0.04) individual/$m^2$ at the understory layer. Ratio of green coverage was 40.0~173.7(93.0)% at the canopy layer, 2.1~79.8(34.9)% at the understory layer and 17.9~64.2(32.9)% at the shrub layer. $Gr{\ddot{u}}volumenzahl$ was $1.43{\sim}6.67(4.13)m^3/m^2$ at the canopy layer, $0.02{\sim}2.01(0.85)m^3/m^2$ at the understory layer and $0.14{\sim}0.58(0.26)m^3/m^2$ at the shrub layer. The ratio of green coverage of street green space on Port Island was higher than that of Seoul, and particularly, the ratio of green coverage and $gr{\ddot{u}}volumenzahl$ at the shrub layer differed, compared to the main street green space in Korea. The result of this study may be applicable to other coastal reclaimed cities in terms of setting methods for street greenery considering the topography structure, planting structure and planting function.

• Journal of the Korean Institute of Landscape Architecture
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• v.38 no.5
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• pp.1-11
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• 2010

The outdoor space of an elementary school is the most familiar and most educational area for children. A paradigm shift in education has demanded a new role and direction for these outdoor spaces. The construction of children-friendly spaces, however, lags behind. The child-participatory design process is very meaningful at a time when many outdoor spaces have difficulties in reflecting the varied and specific demands of children. This study realized the necessity for a design that includes a child-participatory design process in construction the outdoor spaces of elementary schools. Through reference study and a theoretical approach of related laws, this study established a child-participatory design process model and applied it to Seoul Don-Am Elementary School. The design process included playing games and providing interesting tools to increase the participation of children in suggesting and presenting their opinions more freely. The design process of this study is described in five steps(eliciting interest in and recognition of the target space, Understanding children's expectations and the expressing thereof, Establishing factors for planning, Visualizing and arranging spaces, and Decision-making and building a final design plan). This process was applied to the planning and design of an outdoor space for Seoul Don-Am Elementary School. In this study, it is clear that the design of the participators and experts have a different purpose. Thus, the process of the design has more meaning than the final product. In addition, it is expected that an improvement in both tangible and intangible designs will be seen. Using a participatory design process, this study successfully improved the facilities and arrangement planning of an outdoor space. At the same time, it also enhanced the interest and participation of children in the process of creating the kind of school they desire. The significance of this study is that it has suggested an effective model to reflect the demands of children, the true users of the outdoor space, and the results were actually applied to elementary school outdoor planning and designing. This study enhanced the awareness of school members in the process of building the school's outdoor space.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.6
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• pp.28-39
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• 2017

The purpose of this study was to analyze the tendencies of the written test questions regarding the scientific plant names in the subject of scenic planting in the national qualification test for landscape engineers. To achieve this purpose, targeting the 20 questions in the subject of scenic planting, the study chronologically analyzed the types of the presented questions about the scientific names of the plants, the changes in their year-to-year number, and their presentation frequency over the past 11 years from 2006 to 2016. The following was found by an analysis of the tendency of the questions presented over 11 years from 2006 to 2016 regarding the scientific plant names in scenic planting in the written test of the national technical qualification examination for landscape engineers. The number of these questions was 234, and they were classified into 13 items: scientific names, families/genuses/ species, characteristics, barks, roots, foliage, flowers, fruits, properties, places of origin, stalks, leave, and uses. After analyzing the examination question trends per year, the year in which the highest number of questions was given was 2013 at 56.6%; the ratio of questions asking botanical names increased until 2013, although that ratio decreased starting in 2014 due to consistent efforts from the landscaping field. The plant species most frequently asked about were Betula platyphylla and Taxus cuspidata and others frequently asked about included Pinus densiflora, Acer palmatum, Forsythia koreana, Cercis chinensis, Robinia pseudoacacia, Cornus officinalis, Zelkova serrata, Abies holophylla, Camellia japonica, Sophora japonica, Chaenomeles sinensis, which were asked about more than 10 times. The number of plant species presented as question items or choice items was 240 and their presentation frequency was 806, Among these, 66 species were steadily presented more than five times. They were presented 486 times, accounting for 27.5% of all species. The number of the new plant species which began to be presented in 2009 were 119(49.58% including Quercus myrsinaefolia) of all 240 species, indicating that their presentation frequency was gradually increased. As a result of comparative analysis of questions on arbor and shrub, evergreen and leaf abscission that have been presented for recent 11 years, the questions on arbor were more than shrub, the questions on leaf abscission were more than evergreen.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.11
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• pp.7227-7236
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• 2015

The survey revealed that, due to the discharge characteristics of seafood wastewater, irregular inflow loads were caused, making it difficult to treat the wastewater safely. It is crucial for the operation of pressure and floating tanks for the treatment of high-concentration organic wastewater such as seafood wastewater. The survey of operation factors for the pressure and floating tanks revealed this: A/S ratio 0.05 (design criteria 0.01), the pressurized air pressure 8bar(design criteria 6bar), the pressure tank pressure 6bar (design criteria 4.5bar), and HRT 60sec(design criteria: 10sec). Also, the recirculation rate was changed to over 40%(design criteria: 30%), and the surface load rate was changed to under $13.7m^3/m^2{\cdot}hr$(design criteria: under $17.7m^3/m^2{\cdot}hr$); thus, compared to the initial design criteria, the operation factors were changed according to inflow characteristics, thus enhancing the pressure and floating tank performance. The survey of inflow load revealed BOD 140.7%, $COD_{Mn}$ 120.32%, and SS 106.3%, compared to the inflow design criteria, as well as T-N 135.5% and T-P173.3%, higher than the design criteria. The survey of the treatment facility annual operation cost revealed high portions in sludge treatment cost(27.7%) and chemicals costs(26.0%), and the sludge treatment cost will likely further increase due to the ban on ocean dumping. The unit cost for the treatment of seafood wastewater was found to be KRW 3,858 per ton, more than 27 times higher than the sewage treatment cost(KRW 142.6/ton), presumably because the seafood wastewater contains high-concentration organic substances and nutritive salts.