• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.4
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• pp.673-682
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• 2001

The use of resin composites has continued to increase over the last several years. In spite of their growing popularity, composites continue to exhibit a number of undesirable characteristics. One of the major deficiencies of composite restorative resins is their inadequate resistance to wear. Of the multitude of factors that have been associated with wear, subsurface degradation within the restoration is considered to be one. The aim of this study was to evaluate the resistance to degradation of four commercial composite resins in an alkaline solution. This solution with a high concentration of hydroxyl ions is a convenient medium for accelerated degradation of silane coupling and filler particles. The brands studies were Definite($Degussa-H\ddot{u}ls$ AG, Germany), Prodigy(Kerr, USA), Pyramid(Bisco, USA) and Synergy(Coltene, Swiss). Preweighed discs of each brand were exposed to 0.1N NaOH solution at $60^{\circ}C$. After 14 days they were removed, neutralized with HCl, washed with water and dried. Resistance to degradation was evaluated on the basis of following parameters : (a) mass loss(%)-determined from pre-and post-exposed specimen weights : (b) Si loss(ppm)-obtained from ICP-AE analysis of solution exposed to specimens; and (c) degradation $depth({\mu}m)$-measured microscopically (SEM) from polished circular sections of exposed specimens. The results were follows: 1. Mass loss of Synergy was $1.24{\pm}0.002%$, it was the highest, there was no significant difference among the materials. 2. The degree of degradation layer depth of Synergy was $107.83{\pm}2.52{\mu}m$, it was the highest, there was no significant difference among any other materials than Synergy. 3. There was no difference among the four materials in Si loss. 4. The correlation coefficient between mass loss and degradation depth was relatively high(r=0.06, p<0.05). 5. There was no coefficient correlation between Si loss and mass loss, the degree of degradation layer depth and Si loss. 6. When observed with SEM, destruction of bonding is observed between resin matrix and filler.

• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.1
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• pp.65-72
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• 2010

General anesthesia has been researched and developed in dentistry as on type of management technique to sedate patients who may be uncontrollable or require medical consideration. There has been continuous research into this area, but analysis of large set of patients over a sustained period of time is lacking. Thus, this study analyzes the records of patients who received general anesthesia at the Yonsei University Dental Hospital Department of Pediatric and Clinic for the Disabled. 1. Patient's age ranged from 1 to 66, with under 5 being the largest group with 410 members(38.5%). The study included more men than women, with 695 male members(65.3%). 2. Type of dental procedure performed were as follows(per person) : 5.6 Dental restoration; 2.3 Endodontic treatment of deciduous and primary teeth; 2.5 preformed crowning; and 1.6 extractions. Procedures took an average of 100 minutes. 3. 1022 patients(95.9%) received dental care under general anesthesia once and 43 patients(4.1%) received dental care under general anesthesia two or more times. Dentistry under general anesthesia has the many benefit. However, without appropriate post-treatment care, it is difficult to maintain good oral health. Therefore, it is important to improve the efficiency and safety of general anesthesia through future research.

• Trans-
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• v.3
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• pp.55-86
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• 2017

This study begins with the necessity of the concept of reincarnation of film media and the inclusion of specific tendencies of contemporary films as post - cinema comes. Variable movements around recent films Challenging and experimental films show aesthetics that are difficult to approach with the analysis of classical mise en scene and montage. In this way, I review the dispositif proposed by Martin in films that are puzzling to criticize with the classical conceptual framework. This is because the concept of dispositive is a conceptual pile that extends more than a mise en scene and a montage. Dispositif films tend to be non-reproducible and non-narrative, but not all non-narrativef tendencies are dispositif films. Only the dispositif film is included in the flow. Dispositif movement has increased dramatically in the modern environment on which digital technology is based, but it is not a tendency to be found in any particular age. The movement has been detected in classical films, and the dispositif tendency has continued to exist in avant-garde films in the 1920s and some modernist films. First, for clear conceptualization of cinematic dispositif, this study examines the sources of dispositif debates that are being introduced into film theory today. In this process, the theory of Jean Louis Baudry, Michel Foucault, Agamben, Flusser, and Deleuze will help. The concept of dispositif was discussed by several scholars, including Baudry and Foucault, and today the notion of dispositif is defined across all these definitions. However, these various discussions are distinctly different from the cinematic dispositif or dispositif films that Martin advocates. Martin's proposed concept reminds us of the fundamentals of cinematic aesthetics that have distinguished between the mise-en-scene and the montage. And it will be able to reconsider those concepts and make it possible to view a thing a new light or create new films. The basic implications of dispositif are apparatus as devices, disposition and arrangement, the combination of heterogeneity. Thus, if you define a dispositif film in a word, it is a new 'constraint' consisting of rearrangement and arrangement of the heterogeneous elements that make up the conditions of the classical film. In order for something to become a new design, changes must be made in the arrangement and arrangement of the elements, forces, and forces that make up it. Naturally, the elements encompass both internal and external factors. These dispositif films have a variety of possibilities, such as reflection on the archival possibilities and the role of supervision, the reestablishment of active and creative audience, the reason for the film medium, and the ideological reflection. films can also 'network' quickly and easily with other media faster than any medium and create a new 'devised' aesthetic style. And the dispositif film that makes use of this will be a key keyword in reading the films that present the new trend of modern film. Because dispositif are so comprehensive and have a broad implication, there are certainly areas that are difficult to sophisticate. However this will have a positive effect on the future activation of dispositif studies end for end. Dispositif is difficult to elaborate the concept clearly, so it can be accessed from a wide range of dimensions and has theoretically infinite extensibility. At the beginning and end of the 21st century film, the concept of cinematic dispositif will become a decisive factor to dismantle old film aesthetics.

• Korea journal of population studies
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• v.19 no.2
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• pp.107-137
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• 1996

Under-utilization of Korean women's education in the labor market has been observed and pointed out as a waste of valuable human resources. Although education provides women with positive returns when they work, it has been found that Korean women's education is not much related to the likelihood of women's labor force participation. This tendency cannot be explained by micro-economic theory, which says that educated women are more likely to participate in the labor force. Thus, in this analysis, a macro-level explanation is attempted to understand Korean women's economic behaviors in relation to education. Korea's rapid industrialization since 1960 has provided ample job opportunities mostly for less educated women. On the other hand, increasing demand for educated female labor has been moderate. Various restriction against women, especially married women, have prevailed in the Korean labor market. Restrictions against women and the marriage bar tend to be selectively applied to decent white-collar jobs, mostly affecting educated women. Furthermore, there has been no shortage of educated male labor due to its adequate supply. Since Korean women spend most of their adult lives in marriage, married women's low participation in the labor force is a critical factor for the low economic returns to women's education throughout their lifetime. Restriction against married women in the labor market also existed in the past of the United States and the Great Britain. However, along with the expansion of the service sector, married women in great numbers flowed into non-manual jobs. The post-1940 increase of married women in the labor force in those countries can be understood to be a result of a labor shortage for non-manual jobs. Also in Taiwan, which shares many common cultural and economic backgrounds with Korea, the marriage bar has been in decline since the late 1970s, along with an increasing demand for female labor in the service sector. In sum, the changes in the demand structure and the supply of educated male labor force will contribute to the lift of the marrige bar in Korea.

• Journal of Gastric Cancer
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• v.7 no.3
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• pp.152-159
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• 2007

Purpose: Recently, the use of laparoscopic assisted gastrectomy for early gastric cancer has been on the increase and the procedure has been quickly adopted by clincians. However, there are few reports regarding the safety and risk of this type of surgery. The aim of this study is to evaluate the morbidity and to verify the safety of laparoscopic assisted gastrectomy for early gastric cancer. Materials and Methods: A total of 376 patients that had undergone laparoscopic assisted gastrectomy for early gastric cancer between April 2004 and December 2006 were reviewed retrospectively. The clinicopathological characteristics, operative complications, and factors related to complications were evaluated. Results: The overall operative morbidity and mortality rates were 10.6% and 0%, intraoperative morbidity was 1.1% (4 of 376 patients) and post operative morbidity was 9.6% (36 of 376 patients). Most complications required no surgery except for an intestinal obstruction in two cases. Multivariate analysis of risk factors related to operative morbidity determined that age was an independent factor associated with morbidity (P=0.021). Conclusion: The complication rate of laparoscopic assisted gastrectomy is low and most complications can be managed by conservative methods rather than with surgery. There were no specific predicting factors for complications except old age. Laparoscopy is a technically feasible and acceptable surgical modality for early gastric cancer.

• Journal of the Korean Institute of Landscape Architecture
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• v.38 no.5
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• pp.64-79
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• 2010

Students with intellectual disabilities typically have great difficulties communicating their needs and wants and may get frustrated, anxious or show signs of aggressive behaviour. They are often unable to understand the concept of relationships with other people as well. This lack of social communication and interaction leads to poor motivation which increases other areas of difficulty in their lives. Therefore, to teach students with intellectual disabilities, it is essential to find special teaching methods to support their positive behavior. This paper proposes that special educational curriculum for students with intellectual impairments utilize natural environments(forests) and materials. The purpose of this study was to investigate the effects of Educational Programs Utilizing Forests on maladjusted behavior of students with mental retardation and to examine the positive effects of such planning practices. The subjects were middle school students who attended a special school for mentally-retarded students. They were divided into two separate groups- an experimental group and a control group. All subjects received the pre and post test using the same method. This program was applied to the formal educational process of middle school from March 1st to October 30th, 2009. In this experiment the results indicate that the effect of using a natural environment(forest) and the materials within a formal educational curriculum was positive as a type of horticultural therapy and that it supports positive behavior strategies in students with intellectual impairments. The usage of various natural materials including plants and flowers within the natural environments provide students with increased opportunities to participate. Teaching methods including natural materials help teachers engage with their students more easily during routine activities as their interest is already stimulated. This project will help students with intellectual impairments to build skills which enable effective participation and increase independence throughout their lives. This should be embedded into both routine and planned activities of the classroom Also, it offers a needed interior plan for the treatment space through an analysis of psychological factors of how the environment affects students.

• Journal of the Korean Institute of Landscape Architecture
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• v.48 no.4
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• pp.29-40
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• 2020

This study quantitatively and qualitatively analyzes the physical environment for health promotion in urban parks by indicators that were selected in consideration of overseas cases and previous studies. To evenly distribute the areas to be evaluated by region, Seodaemun Independence Park, Hongneung Park, Gocheok Park, Sillim Park, Cheongdam Park, Gaepo Park, and Sungin Park were selected among the old neighborhood parks already established in Seoul. The evaluation indicators consist of quantitative indicators (12 factors classified into the three categories of the surrounding environment, the park characteristics, and the park facilities) and qualitative indicators (14 factors classified according to the five categories of accessibility, safety, convenience, activities, and amenities). These indicators were selected after conducting advisory meetings with experts in the field. The physical environment perception factors were evaluated by experts and investigators by field inspections and were rated on a three-point scale (high, medium, low). According to the results of the analysis, first, not only were exercise facilities and trails, but also various factors which support health activities, such as rest areas, leisure spots, and cultural facilities, as well as accessibility, cleanliness, and drinking water facilities are important indicators for health promotion. Second, even if the requirements are met for quantitative factors, several inconveniences hinder the actual implementation or use in the qualitative evaluation. Thus, both quantitative and qualitative evaluations must be simultaneously performed for the proper judging of the physical environment of a park. Third, upon conducting a qualitative evaluation of the physical environmental factors, score differences depended on the evaluated categories in each park. These differences show that indirect indicators, such as accessibility, safety, and facility convenience are insufficiently equipped compared to direct indicators, such as activity, which includes exercise facilities and fitness centers for health promotion. As the utilization rate of parks is increasing due to COVID-19, more efforts should be made to improve park services in the post-corona era. To promote such services, it is necessary to regularly evaluate parks based on both quantitative and qualitative indicators and to contemplate services not only through direct factors but also indirect factors and security measures.

• Archives of design research
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• v.17 no.1
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• pp.339-346
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• 2004

Matrix, produced by Larry & Andy Wachowski, was relatively precisely dealt with the cyber world. After the movie was released, it had a mania for the movie and was adopted into a various forms of cultural products. It was remade not only into the parodies of the other movies and TV programs, but also the clothes and miscellaneous items of the movie were reincarnated as an unique cultural trend. The cause of the popularity is the fresh storyline as well as the sophisticated visual effects and good-looking actors. The agony of the protagonist was connected with the people outside the movie who are yearning for the ideal world. He was confused at the fact that his circumstances which were believed as the real world were not tortally true, complicated between the sensually phisical truth and the spiritual truth and had an will for the freedom that would ransack the truth and save the other people from the fictitious world. Consequently, the movie has got sympathies with many audiences suggesting the situation that has no a firm belief of the reality, the difference between the real and the cyber world is meaningless and the faked images of the high-technology are overturned This thesis tries to study the present that the real images are excessly duplicated and consumed, related to the Jean Baudrillard's theory, 'Hyperreel'. Replaced the real objects by a technical programming in the Matrix world, there happens the image-violence that the true nature is slaughterred by images. In the world where the reproducts are more actual than the reality and pretends to be real, only semiotics are consumed and produced. That is to say, the tortally programmed images has no references and aims, therefore should be produced in an 'impediment-strategy' like a faked crisis. That is the step of 'Simulation' that artificially reincarnates the real. Based upon the Baudrillard's theory, 'Simulacre', this study tries to research today's post-modern situation that the boundary of the real world and the faked copy is vague and vanishing, through the analysis of the cyber world of the movie 'Matrix'.

• Restorative Dentistry and Endodontics
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• v.35 no.2
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• pp.88-95
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• 2010

The purpose of this study was to compare the root canal shaping ability of 4 rotary NiTi instruments in simulated root canals. For the preparation of thirty two curved root canals, Mtwo instruments using "single length"technique, and Profile, ProTaper Universal, and K3 using crown-down technique (N = 8) were used. All canal samples were prepared by reaching an apical canal size of #30. Pre- and post-instrumentation digital images were recorded and an assessment of canal shape was determined using a computer image analysis program SigmaScan Pro (Systat Software Inc., San Jose, CA, USA). The changes of the dimension of inner walls of canals, (2) the changes of the dimension of outer walls of canals, and (3) the centering ratio were measured at 7 measuring points, and then data were statistically analyzed using one-way ANOVA and Duncan's test. The results were as below; 1. The root canal shaping ability of Profile was significantly faster than that of other rotary NiTi instruments (p < 0.05). 2. The deformation and fracture of all instruments used for this study were not experienced. 3. In the degree of changes of the dimension of inner walls of canals, Profile demonstrated the lowest changes of the dimension of inner walls of canals except at the measuring points of the 1 and 2 mm (p < 0.05). However, the ProTaper Universal showed the highest changes of the dimension of inner walls of canals at all measuring points (p < 0.05). 4. In the degree of changes of the dimension of outer walls of canals, Mtwo demonstrated the lowest changse of the dimension of outer walls of canals except at the measuring point of the 1 mm (p < 0.05). However, Profile exhibited the highest changes of the dimension of outer walls of canals at the measuring points of 3 and 4 mm and ProTaper Universal and K3 showed the largest changes of the dimension of outer walls of canals at the measuring points of 1, 2, 6, and 7 mm (p < 0.05). 5. In degree of centering ratio, Profile demonstrated the least centering ratio comparing with the centering ratio shown by other NiTi instruments at the measuring points of 1, 4, 5, and 6 mm. Results suggest that in the coronal part of canal preparation, active cutting files such as ProTaper Universal may efficiently flare the canal orifice and form a better taper, and in the apical part of the canal, files which have a better centering ability such as Profile may maintain the original canal curvature and reduce the shaping time.

• Restorative Dentistry and Endodontics
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• v.41 no.2
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• pp.91-97
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• 2016

Objectives: The purpose of this ex vivo study was to compare the antifungal activity of a synthetic peptide consisting of 15 amino acids at the C-terminus of human ${\beta}$-defensin 3 (HBD3-C15) with calcium hydroxide (CH) and Nystatin (Nys) against Candida albicans (C. albicans) biofilm. Materials and Methods: C. albicans were grown on cover glass bottom dishes or human dentin disks for 48 hr, and then treated with HBD3-C15 (0, 12.5, 25, 50, 100, 150, 200, and $300{\mu}g/mL$), CH ($100{\mu}g/mL$), and Nys ($20{\mu}g/mL$) for 7 days at $37^{\circ}C$. On cover glass, live and dead cells in the biomass were measured by the FilmTracer Biofilm viability assay, and observed by confocal laser scanning microscopy (CLSM). On dentin, normal, diminished and ruptured cells were observed by field-emission scanning electron microscopy (FE-SEM). The results were subjected to a two-tailed t-test, a one way analysis variance and a post hoc test at a significance level of p = 0.05. Results: C. albicans survival on dentin was inhibited by HBD3-C15 in a dose-dependent manner. There were fewer aggregations of C. albicans in the groups of Nys and HBD3-C15 (${\geq}100{\mu}g/mL$). CLSM showed C. albicans survival was reduced by HBD3-C15 in a dose dependent manner. Nys and HBD3-C15 (${\geq}100{\mu}g/mL$) showed significant fungicidal activity compared to CH group (p < 0.05). Conclusions: Synthetic HBD3-C15 peptide (${\geq}100{\mu}g/mL$) and Nys exhibited significantly higher antifungal activity than CH against C. albicans by inhibiting cell survival and biofilm.