• Journal of the Korean Geographical Society
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• v.50 no.2
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• pp.185-201
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• 2015

This paper suggests how Korean housemaids, called Sikmo, and Korean-Chinese migrant domestic workers have similar class positions and therefore form a dual identity in their interactions with female employers. rough spoken stories of the experiences of 27 females from Seoul, including Korean-Chinese domestic workers, Korean housemaids, and their employers, this research effectively overcomes the dichotomous discourse of natives versus foreigners. Instead it suggests the new interpretation that it is not foreignness but class inferiority of the domestic workers that plays a key role in establishing relationships with employers. Korean housemaids and Korean-Chinese domestic workers, both groups of whom are migrant workers, have developed coping strategies to enhance their labor value by spatially relocating themselves from their home society to a new society. They possess a similar labor status in women's history, being of low income, low education, and rural births. Consequently, these women experience 'translocal anchoring,' meaning their identities are intertwined with that of their home societies, and employers perceive them based on the characteristics of these places. The Korean employers perceive that the domestic workers' morality and intellectuality are inferior based on their class differences. This stigmatizing process leads employers to regard domestic workers as ambivalent people, not only threatening outsiders but also objects of pity, needing love and protection of their employers. The employers educate them culturally, teaching them skills to survive in the urban environment. These skills include cooking and language, in addition to advice on long-term plans to blend into society.

• Journal of Environmental Impact Assessment
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• v.26 no.6
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• pp.385-403
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• 2017

This study showed the national ecosystem classification for the spatial standards of ecosystems-based approaches to the risk assessments and adaptation plan. The characteristics of climate change risk assessment, implement national adaptation plans, and ecosystem/habitat classification status was evaluated. Focusing on the land cover classification widely utilized as spatial data for the assessments of biodiversity and ecosystem services in the UK and other countries in Europe, the applicability of the national land cover classification for climate change risk assessments was reviewed. Considering the ecosystem classification for climate change risk assessment and establishing adaptation measures, it is difficult to apply rough classification method to the land cover system because of lack of information on habitat trend by categorization. The results indicated that forest ecosystems and agro-ecosystem occupied 62.3% and 25.0% of land cover, respectively, of the entire country. Although the area is small compared with the land area, wetland ecosystem (2.9%), marine ecosystem (0.4%), coastal ecosystem (0.6%), and urban ecosystem (6.1%) can be included in the risk assessments. Therefore, it is necessary to subdivide below the medium classification for the forest and agricultural land, as well as Inland wetland, which has a higher proportion of habitat preference of taxa than land area, marine/coastal habitat, and transition areas such as urban and natural ecosystem.

• Applied Microscopy
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• v.27 no.3
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• pp.265-279
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• 1997

This study aims to demonstrate the effect of chitosan, one of the natural chelator, on the ultrastructural changes in the mouse liver caused by cadmium. A total of 60 healthy ICR that weighted 30 gm $({\pm}2gm)$ was used for experiment. The experimental group was divided into three groups; group A, B, and C. The group A and B administrated cadmium (4.0 mg/kg) to the intraperitoneal after pretreated with chitosan (0.5% solution) for 30 and 7 days, respectively. Each group was observed at 12, 24, 48, 72 hours and one week after injected cadmium. The results were as follows: 1. Group A The nuclear membrane and the chromatin were normal shapes at overall the time. The inner and outer membranes of the mitochondria damaged a little but almost normal in shapes. And electron-density showed slightly compacted. some enlarged rER (rough endoplasmic reticulum) showed at 12 hours. At 48 hours, typical lamellae of the rER were reformed, and a lot of transvesicles observed around them. To 48 hours, sER (smooth endoplasmic reticulum) was slightly dilated. From 72 hours, sER rehalizated in normal shape. 2. Group B Nuclear membranes were rounded-shape and chromatin showed evenly. To 72 hours, a lot of mitochondria observed around rER and development of cristae showed weakly. But at one week, cristae were clear and electron-density of matrix showed high. At 72 hours lamellae of rER showed some broken, but were reformed at one week. Also at one week, glycogen granules evenly showed over cytoplasm. 3. Group C At 12 hours, Nucleus showed the condensation of nuclear membrane and clear condensation at 24 hours. However, nuclear membrane had a slightly rounded-shape from 72 hours. From 12 hours to the one week, mitochondria showed the dilation of inner cavity and weak development of cristae. Also electron-density of matrix was a little low. Occasionally, destruction of inner and outer membrane observed at one week. The dilation of cisternae and destruction of lamellae of rER showed from 12 to 48 hours. From 72 hours, rER showed slightly dilated only. And lamella observed at one week. In sER, dilation of inner cavity was observed during whole period. These results suggest that chitosan attenuates the toxic effect of the cadmium in the mouse liver.

• Journal of Dental Rehabilitation and Applied Science
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• v.31 no.3
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• pp.203-211
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• 2015

Purpose: The purpose of this study was to investigate the reosseointegration periods when the rough surface implants, which had complete bone-implant ankylosis, suddenly losed the osseointegration. Materials and Methods: The implants with RBM surface treatment were inserted into both tibias of 23 rabbits. Two implants were submerged into each side. After six weeks, the primary removal torque was measured by Digital torque gauge, and then the implants were replaced and submerged to estimate the level of reosseointegration. After assigned healing periods for each group, the removal torque was measured again. BIC (Bone-Implant contact, %) ratio was measured through histomorphometric analysis.Paired t-test was processed by SPSS 14.0. One-way ANOVA and Tukey's post-hoc test was processed to analyze statistically significant differences among the groups. Results: In comparison with the primary removal torque, the secondary removal torque was increased after 11 days and significantly increased from 2 weeks. In fluorochrome labeling, the origin of mineralization was observed after 7 days, which showed as fluorescent bands around the bone-implant interfaces. After 11 days, the bone formation was apparent, and it is increased continuously with the passage of the time. Conclusion: In 11 days after the implant replacement, the secondary removal torque was almost as same as the primary value, and was significantly higher from 2 weeks. The mineralized shapes were observed in 7 days after the implant replacement, and then the bone formation appeared visibly in 11 days.

• Korean journal of applied entomology
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• v.54 no.4
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• pp.351-357
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• 2015

The two-spotted spider mite Tetranychus urticae Koch, overwinters in apple culture areas of apple orchards. The mite overwinters in various places on the apple trees, usually in groups of 5-15 females. Overwintering females were mostly found in bark crevices with the hibernation cocoons of the oriental fruit moth, Grapholita molesta Busck. They were also found in small crevices of the bark, and in pedicels left after fruit harvesting. Furthermore, overwintering females were found on rough bark at the bases of buds and spurs, on small limbs and twigs, and in limb crevices and forks. Empty scales of dead diaspidids and coccids, as well as cocoons of lacewings and mummies of parasitized aphids sporadically found on trees, were found to be less common overwintering sites for females of the two-spotted spider mite. In two successive years, the mortality of overwintering females was very high, reaching approximately 72 and 80%. This could be due to the low temperature of winter season in Korea and the low cold tolerance of the mite.

• Journal of Periodontal and Implant Science
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• v.36 no.2
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• pp.319-334
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• 2006

Mechanical and chemical methods are the two ways to treat the implant surfaces. By using mechanical method, it is difficult to eliminate bacteria and by-products from the rough implant surface and it can also cause the structural change to the implant surface. Therefore, chemical method is widely used in order to preserve and detoxicate the implant surface more effectively. The purpose of this study is to evaluate the effect of tetracylcline-hydrochloride(TC-HCI) on the change of implant surface microstructure according to application time. Implants with pure titanium machined surface, SLA surface and porous surface were used in this study. Implant surface was rubbed with sponge soaked in 50mg/ml TC-HCI solution for $\frac{1}{2}$ min., 1 min., $1\frac{1}{2}$ min., 2 min., and $2\frac{1}{2}$ min. respectively in the test group and with no treatment in the control group. Then, specimens were processed for scanning electron microscopic observation. 1. Both test and control group showed a few shallow grooves and ridges in pure titanium machined surface implants. There were not significant differences between two groups. 2. In the SLA surfaces, the control specimen showed that the macro roughness was achieved by large-grit sandblasting. Subsequently, the acid-etching process created the micro roughness, which thus was superimposed on the macro roughness. Irrespective of the application time of 50mg/ml TC-HCI solution, in general, test specimens were similar to control. 3. In the porous surfaces, the control specimen showed spherical particles of titanium alloy and its surface have a few shallow ridges. The roughness of surfaces conditioned with tetracycline-HCI was lessened and seen crater-like irregular surfaces relative to the application time. In conclusion, pure titanium machined surfaces and SLA surfaces weren't changed irrespective of the application time of tetracycline-HCI solution. But the porous surfaces conditioned with tetracycline-HCI solution began to be slightly changed from 2 min. This results are expected to be applied to the regenerative procedures for peri-implantitis treatment.

• Journal of Korean Home Economics Education Association
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• v.21 no.4
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• pp.19-33
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• 2009

The purpose of this study was to investigate fast food consumption, awareness of fast food and food habit of middle school students in Wonju area according to their intake frequency of fast foods. Subjects were categorized into 3 groups according to intake frequency of fast foods : frequent users($\geq$ 1 times/week, 29.5%) users(2~3 times/month, 50.7%), non-users($\leq$ 1 time/month, 19.8%). As for the purpose of eating fast food, many ate fast food between meals. The most favorite fast food was chicken regardless of intake frequency, followed by pizza, hamburger, the reason being that it tasted good. Regarding if there was any room for improvement, the largest number of the students asked for inexpensive price, irrespective of fast food intake frequency. Compared to users, non-users intake more diverse foods, vegetables, dairy products, fruits, protein foods and seaweed. Users or frequent users of fast food more felt drowsy, cold in the hand and foot, rough skin symptoms than non-users. In conclusion, frequent consumption of fast foods can lead unbalanced diet intakes for middle school students, and those who consumed fast foods frequently showed undesirable food habits in their daily meal.

• Restorative Dentistry and Endodontics
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• v.18 no.1
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• pp.1-26
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• 1993

The purpose of this study was to investigate the effect of acid etching on the surface appearance and fracture toughness of five glass ionomer cements. Five kinds of commercially available glass ionomer cements including chemical curing filling type, chemical curing lining type, chemical curing metal reinforced type, light curing tilling type and light curing lining type were used for this study. The specimens for SEM study were fabricated by treating each glass ionomer cement with either visible light curing or self curing after being inserted into a rubber mold (diameter 4mm, depth 1mm). Some of the specimens were etched with 37% phosphoric acid for 0, 15, 30, 60, go seconds, at 5 minutes, 1 hour and 1 day after mixing of powder and liquid. Unetched ones comprised the control group and the others were the experimental groups. The surface texture was examined by using scanning electron microscope at 20 kV. (S-2300, Hitachi Co., Japan). The specimens for fracture toughness were fabricated by curing of each glass ionomer cement previously inserted into a metal mold for the single edge notch specimen according to the ASTME399. They were subjected to a three-point bend test after etching for 0, 30, 60, and 90 seconds at 5 minutes-, 1 hour-and 1 day-lapse after the fabrication of the specimens. The plane strain fracture toughness ($K_{IC}$) was determined by three-point bend test which was conducted with cross-head speed of 0.5 mm/min using Instron universal testing machine (Model No. 1122) following seven days storage of the etched specimens under $37^{\circ}C$, 100% humidity condition. Following conclusions were drawn. 1. In unetched control group, crack was present, but the surface was generally smooth. 2. Deterioration of the surface appearance such as serious dissolving of gel matrix and loss of glass particles occured as the etching time was increased beyond 15 s following Immediate etching of chemical curing type of glass ionomer cements. 3. Etching after 1 h, and 1 d reduced surface damage, 15 s, and 30s etch gave rough surface appearance without loss of glass particle of chemical curing type of glass ionomer cements. 4. Light curing type glass ionomer cement was etched by acid, but there was no difference in surface appearances according to various waiting periods. 5. It was found that the value of plane stram fracture toughness of glass ionomer cements was highest in the light curing filling type as $1.79\;MNm^{-1.5}$ followed by the light curing lining type, chemical curing metal reinforced type, chemical curing filling type and chemical curing lining type. 6. The value of plane stram fracture toughness of the chemical curing lining type glass ionomer cement etched after 5 minutes was lower than those of the cement etched after 1 hour or day or unetched (P < 0.05). 7. Light curing glass ionomer cement showed Irregular fractured surface and chemical curing cement showed smooth fractured surface.

• Archives of Plastic Surgery
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• v.37 no.4
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• pp.340-345
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• 2010

Purpose: Recently, bioceramics have become popular as a substitute graft material for reconstruction of bony defect after trauma or tumor surgery. Among the bioceramic materials, hydroxyapatite (HA) is favored due to its biocompatibility. HA scaffold is composed of the interconnected reticular framework, macropores and micropores. Macropores play an important role in cell migration, nutrients supply and vascular ingrowth. On the other hand, a number of micropores less than $10{\mu}m$ form an irregular surface on HA scaffolds, which prevents the osteoblast from adhering and proliferating on the surface of HA scaffold. Methods: In this study, three different groups were designed for comparison. In the first group (group A), conventional method was used, in which HA pellet was applied without surface pretreatment. The second group (group B) was given a HA pellet that has been coated with crystalline HA solution prior to application. In the third group (group C), the same method was used as the second group, where the pretreated HA pellet was heated ($1250^{\circ}C$, 1 hour) before application. Osteoblast-like cells ($2{\times}10^4$/mL) were scattered onto every pellet, then they were incubated in 5% $CO_2$ incubator at $37^{\circ}C$ for twelve days. During the first three days, osteoblast cells were counted using the hemocytometer daily. ALP activity was measured on the 3, 6, 9 and 12 culture days using the spectrophotometer. Results: Under SEM, group A showed a surface with numerous micropores, and group B revealed more rough crystal surface. Group C revealed a fused crystal appearance and flattened smooth surface. In proliferation and ALP activity of osteoblast cells, group C showed better results compared to group B. Group A which lacks pretreatment of the surface showed less osteoblast proliferation and ALP activity than group C, but showed better results than group B. Conclusion: We found that crystallized HA with heat treatment method enhances the osteoblasts proliferation and differentiation on the surface of HA pellets.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.21 no.2
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• pp.121-127
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• 2010

Background and Objectives : Unilateral vocal fold paralysis is generally treated using injection laryngoplasty or voice therapy. However, the decision of treatment method is dependent on clinician's preference and hospital facilities without specific criteria. The purpose of the study was to examine factors predictive of voice therapy outcome in patients with unilateral vocal fold paralysis. Materials and Method : 38 patients diagnosed as unilateral vocal fold paralysis, aged from 24 to 81 years and undergone voice therapy more than 1 month were included. After 3 to 12 (mean 5.1) sessions of voice therapy, subjects had divided into responder group (RG, 28 patients) and non-responder group (NRG, 10 patients) according to G scale change. Paramters of perceptual assessment, acoustic and aerodynamic measure, and videostroboscopy were compared between two groups, and factors predictive of voice therapy result were analyzed. Results : RG patients showed significantly reduced rough, breathy, asthenic voice after voice therapy. Change of MPT and MFR was more substantial in RG than in NRG. By videostroboscopy, RG patients showed significantly more mucosal wave symmetry, glottal closure, reduced glottal gap index during the closed phase of phonation, while NRG patients showed more occurrences of abnomal supraglottic activities during phonation (p < 0.05). Poor outcome of voice therapy significantly associated with increased asthenic scale, short MPT, and less glottal closure (p=0.02). In addition, 90% of patients with MPT more than 5 seconds were in RG, whereas 56% of patients with MPT less than 5 secondes were in RG. Conclusion : Voice therapy is useful for large proportion of patients with unilateral vocal fold paralysis as an initial treatment method. However, patients with large asthenia scale, large glottic gap or MPT less than 5 seconds tend to have poor voice therapy outcome, and early injection laryngoplasty maybe recommended for these patients.