• Journal of Global Scholars of Marketing Science
• /
• v.16 no.3
• /
• pp.125-142
• /
• 2006

The purpose of this study is to Baekje Cultural Festival development & reform measure by using tourist behavior characteristic of using a correspondence analysis. This study searches choice attributes factors to compare and analyzes satisfaction with importance of each regional culture festival based on choice attributes factor to grasp main tourists' behavioral character about visitors of Buyeo baekje cultural festival that can be called representative regional cultural festival in Korea. Also, execute confrontation agreement test that is kind of multidimensional scaling, wish to examine preference by age and by companion of Buyeo baekje cultural festivals that is regional unique festival, and contribute attract foreign tourist to korea enlargement. And analyze through multiple regression analysis whether festival choice attributes factor exerts effect that is some in revisiting intention, I wish to consider desirable development and improvement plan that can analyze problem by this strength and weakness, raise more attractive foreign tourist to korea and incomes in Buyeo baekje cultural festival hereafter.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.22 no.2
• /
• pp.173-180
• /
• 2006

Objectives The aim of this study is to compare the quality of root canal preparation completed using MFile-$System^{(R)}$ instrument ( Komet, Gebr.Brsaseler, Germany) and conventional stainless steel file in the canals of Maxillary molar teeth that had a canal curvature between $25^{\circ}$ or more Materials & Methods Buccal canals of 24 first and second maxillary molar teeth, extracted for periodontal and prosthetic reasons were used. Tissue fragments and calcified debris were removed from teeth by scaling and the teeth were stored in 10% formalin solution for 24 hour. Then, teeth were stored in saline until used. To be included the roots had to have completed formed apices and angle of curvature ranging between $25^{\circ}$ or more according to the criteria described by Schneider(1971). Palatal and Second mesiobuccal canals were not included. Teeth were embedded into transparent acrylic. The teeth were randomly divided into two experimental groups. All teeth were scanned by Dental CT (PSR9000N, Asahi, Japan) to determine the root canal shape before instrumentation. Image slices were prepared from the apical end point to the pulp chamber. The first two sections were 2 mm from the apical end of root and 2 mm below the orifice. Further section was recorded, dividing the distance between the sections of apical and coronal levels into two equal lengths. 12 teeth were instrumented using stainless steel fileand another 12 teeth were instrumented using MFile-$System^{(R)}$. Following the completion of the instrumentation, the teeth were again scanned and compared with the cross sectional images taken prior to canal preparation. Amount of transportation and centering ability was assessed. Student's t-test was used for statistical analysis. Result Less transportation occurred with MFile-$System^{(R)}$ rotary instrumentation than stainless steel instrument. MFile-$System^{(R)}$ had better centering ability than stainless steel instrument. Conclusion MFile-$System^{(R)}$ rotary instrumentation transported canals less and had good centering ability.

• Journal of Periodontal and Implant Science
• /
• v.25 no.3
• /
• pp.529-538
• /
• 1995

It has been believed that the increased release of free oxygen radicals ($O_2^-,H_2O_2$, and $OH^-$) might be a factor in the pathogenesis of periodontal diseases. Antioxidant enzymes such as glutathione peroxidase(GSH-PX) and catalase can protect the tissue damage from the $H_2O_2$. In order to investigate the GSH-PX and catalase activity in the blood plasma and red blood cells(RBCs) of the patients with periodontitis, 19 patients who had good general health, attachment loss more than 6 mm and bone loss were selected as periodontitis group, 7 patients who had severely inflamed gingiva were selected as gingivitis group, and 15 volunteers with good general and periodontal health were selected as normal group. 17 of 26 patients were performed scaling and root planing to reduce the gingival inflammation for gingivitis and periodontitis groups, and were selected as posttreatment group. After blood plasma and RBCs were collected and separated 1 ml of peripheral blood from each subject, GSH-PX activity in blood plasma and RBCs was measured by the same method that Stefan et al. did, and catalase activity in RBCs was measured by the same method that Beers et al. did. The difference of GSH-PX and catalase activity between normal, gingivitis, and periodontitis groups was statistically analyzed by ANOVA with SPSS/PC+ program, and the difference between pretreatment and posttreatment groups was analyzed by Student t-test. The results were as follows : 1. GSH-PX activity in blood plasma was significantly lower in the gingivitis group($0.8683{\pm}0.0658$), periodontitis group($0.7130{\pm}0.1333$) than in the normal group($1.0241{\pm}0.0801$)(p<0.05), and GSH-PX activity in RBCs was significantly lower in the gingivitis groupt. $0.8156{\pm}0.1167$), periodontitis group($0.7533{\pm}0.1185$) than in the normal group($l.1963{\pm}0.2044$)(P<0.05), but there was no statistical significance in the difference of GSH-PX activity in RBCs between the gingivitis group and periodontitis group(p>0.05). 2. Catalase activity in RBCs was siginficantly lower in the periodontitis group($117.34{\pm}35.01$) than in the normal group($l52.38{\pm}32.09$)(p<0.05). 3. GSH-PX activity in blood plasma was significantly increased in the posttreatment groupe $1.0376{\pm}0.2820$) compared to the pretreatment group(0.7608 0.1600) (p<0.05), and GSH-PX activity in RBC was significantly increased in the posttreatment group($1.0421{\pm}0.2330$) compared to the pretreatment group($0.7728{\pm}0.1210$)(p<0.05). 4. There was no statistical significance in the difference of catalase activity in RBCs between the pretreatment group($112.04{\pm}43.65$) and posttreatment group($l33.41{\pm}39.16$)(p>0.05).The results, within the limits of the present experiment, suggest that the lowered activity of GSH-PX and catalase in blood plasma and RBCs may be related with periodontopathogenesis.

• Journal of Korean society of Dental Hygiene
• /
• v.9 no.4
• /
• pp.768-783
• /
• 2009

Objectives : The purpose of this study was to analyze dental records performed through a dental hygiene process and provide basic data on clinical training education for dental hygienists. Methods : The dental hygiene records of 440 senior dental hygiene students in Y University from March 2005 to September 2008, were examined. The needs of the clients confirmed by the dental hygiene diagnosis was based on Human Need Theory. The client's needs and the number of visits were analyzed according to the general characteristics(gender, age). The contents of the dental hygiene implementation performed according to the needs were divided into dental hygiene care and oral health education. The dental hygiene evaluation was classified into 'Met of Goal', 'Partially Met of Goal', and 'Unmet of Goal' according to the dental hygiene diagnosis. Data analysis was performed for the Frequency statistics and a Fisher's exact test using SPSS 12.0K for Windows. Results : 1. The clients were mostly aged in their 20's(307 clients). 2. The dental hygiene care usually performed was 'Scaling' and 'Recommendation to visit a dental clinic', and the education performed was 'How to brush teeth'. The implementation result from the need to Freedom of Stress was as simple as 'Be careful when treating' and 'Explanation of medical treatment and tools'. 3. The dental hygiene evaluation showed a higher met rate in the field of education than in that of the dental hygiene care. The reason for unmet the goal was 'Lack of the client's efforts and they didn't visit dental clinic'. Conclusions : The search for a range of clients for dental hygiene process should be made through effective connections between the local community institutions and schools. It was suggested that they should be strength the practical exercises for clients suffering dental anxiety and stress in dental treatments. In addition, education and attempts to motivate the clients should be performed according to their characteristics.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.12
• /
• pp.230-236
• /
• 2019

Recently, issues related to the quality of concrete have continuously resulted in surface quality problems, such as the exfoliation of concrete surfaces due to the cost reduction of cement and poor quality fine aggregate, scaling of surfaces caused by laitance, and plastic shrinkage cracks. Prompted by social issues, the application of a photo catalyst to road structures is being attempted to solve the environmental problems caused by fine dust and automobile exhaust. In this study, chemical admixtures were developed to improve the surface quality of concrete and to apply and distribute titanium dioxide in nanoscale sizes to provide basic data for the development of a photocatalyst-curing agent. As a result of the experiment, silicon and silane were reviewed as a raw material as a curing agent to develop a high performance curing agent with better film performance than conventional curing agents because they could form a film quickly on a fresh concrete surface. The distributed stability of the ultrasonic disperser showed the best performance through an outdoor test for four weeks to review the dispersion measures for the application of nanomaterials.

• International Journal of Highway Engineering
• /
• v.17 no.3
• /
• pp.85-95
• /
• 2015

PURPOSES : Recently, bonded concrete overlay has been used as an alternative solution in concrete pavement rehabilitation since its material properties are similar to those of the existing concrete pavements. Deteriorated concrete pavements need rapid rehabilitation in order to prevent traffic jams on Korean expressways. Moreover, speedy and effective repair methods are required. Therefore, the use of bonded concrete overlay with ultra-rapid hardening cement has increased in an effort to reopen promptly the expressways in Korea. However, mobile mixer is required for ultra-rapid hardening cement concrete mixing in the construction site. The use of mobile mixer causes various disadvantages aforementioned such as limitation of the construction supply, open-air storage of mixing materials, increase in construction cost, and etc. In this study, therefore, hydration accelerator in-situ mixing on polymer modified concrete produced in concrete plant is attempted in order to avoid the disadvantages of existing bonded concrete overlay method using ultra-rapid hardening cement. METHODS : Bonded concrete overlay materials using ultra-rapid hardening cement should be meet all the requirements including structural characteristics, compatibility, durability for field application. Therefore, This study aimed to evaluate the application of hydration accelerator in-situ mixing on polymer modified concrete by evaluating structural characteristics, compatibility, durability and economic efficiency for bonded concrete overlay. RESULTS : Test results of structural characteristics showed that the compressive, flexural strength and bond strength were exceed 21MPa, 3.15MPa and 1.4MPa, respectively, which are the target strengths of four hours age for the purpose of prompt traffic reopening. In addition, tests of compatibility, such as drying shrinkage, coefficient of thermal expansion and modulus of elasticity, and durability (chloride ions penetration resistance, freezing-thawing resistance, scaling resistance, abrasion resistance and crack resistance), showed that the hydration accelerator in-situ mixing on polymer modified concrete were satisfied the required criteria. CONCLUSIONS : It was known that the hydration accelerator in-situ mixing on polymer modified concrete overlay method was applicable for bonded concrete overlay and was a good alternative method to substitute the existing bonded concrete overlay method since structural characteristics, compatibility, durability were satisfied the criteria and its economic efficiency was excellent compare to the existing bonded concrete overlay methods.

• International Journal of Highway Engineering
• /
• v.11 no.3
• /
• pp.51-60
• /
• 2009

This study investigates the fresh state characteristics, strength, chloride ion penetration resistance and freeze-thaw resistance of the suggested high strength-high durability cement concrete pavement. The required workability and air content could be achieved by using an appropriate admixtures. However its dosage should be carefully determined through field trial batches. Compressive strength increased with the increased cement content and, in particular, high cement volume concrete continuously developed strength up to 90 days. No clear relationship, however, existed between flexural strength and cement content. Chloride penetration resistance seemed as a function of curing age rather than the cement content. Freeze-thaw resistance test was conducted using two different coolants, tap water and 4% NaCl solution. When the tap water was used no severe damage was observed up to 300 cycles regardless the air content. Under 4% NaCl solution, specimens of 326kg/$m^3$ cement content showed severe damage with surface scaling. Based on the experimental investigations herein, it is highly recommended that the cement content be greater than 400kg/$m^3$ for strength-high durability cement concrete pavement structures.

• Journal of Soil and Groundwater Environment
• /
• v.8 no.2
• /
• pp.55-61
• /
• 2003

The objective of this study was to investigate the characteristics of nitrate removal by conducting the column test in order to see the performance of surfactant modified zeolite (SMZ) as a permeable reactive barrier material. The prediction of nitrate removal was tested using the one-dimensional advective-dispersive model fitted to the experimental breakthrough curve. A methodology for scaling up to in-situ permeable reactive barrier was also proposed. The breakthrough of nitrate in the column packed with SMZ was well predicted using linear equilibrium adsorption model. The breakthrough time and half-life obtained by breakthrough experiment with variation of flowrates were decreased with the increase of flowrates. When 10㎥/day of groundwater containing the 50 mg/l of nitrate is to be treated to satisfy the potable water quality criteria (10 mg/l) by SMZ reactive barrier, 300 tons of SMZ and about 6 years of breakthrough time will be required, suggesting that 165 million wons are needed as barrier material expenses in each 6 years besides the initial design and construction expenses and the minimal monitoring and maintenance expenses.

• Journal of Korean society of Dental Hygiene
• /
• v.7 no.4
• /
• pp.419-431
• /
• 2007

The setting of dental hygiene clinics is very important to dental hygiene education, which is the place not only to educate students but also to care clients. The purpose of this study is to provide basic research material for improvement of dental hygiene care system in dental hygiene clinics by analyzing the client satisfaction. A questionnaire survey by means of self-entry method was conducted to find out satisfaction of the client, who was visited to the dental hygiene clinics in the department of dental hygiene, Yonsei University. An analysis of frequency, one way ANOVA and T-Test were performed through SPSS 12.0K program. 1. Most clients were mainly composed of students in Wonju College of Medicine. 2. The clients visited for scaling(85.8%) and oral examination(9.73%) were much than treatment(4.42%). 3. Clients aged 21 to 25 were relatively lower in satisfaction with the facilities, system, attitude than any other ages. 4. The dental hygiene students are the lowest group in satisfaction with the facility, system, attitude than medical and nursing students. 5. The clients satisfaction with dental hygiene clinics was decreased in reverse proportion to visiting frequency. 6. Most of the clients pointed out the problems of appointment system(54.0%) and fee(23.0%), which should be improved than any other operation conditions. 7. Most of the clients were not satisfied with chair time and pain during care. 8. Most clients recognized to receive the better care service than other dental offices(81.3%). Especially, they paid attention to oral health education using phase-contrast microscope. 9. Many clients were dissatisfied with facilities of the dental hygiene clinics(71.7%). The problems of appointment system(54.0%) and chair time of dental hygiene care services(63.6%) had also inconvenienced to clients. The dental hygiene clinics in school play a crucial role in dental hygiene education to foster the student to be competent as a professional dental hygienist in the future. Therefore, well-organized dental hygiene care program based on dental hygiene process is essential. It is also required to improve the environment of dental hygiene clinics including facilities, appointment system and fee etc.

• Journal of the Korean GEO-environmental Society
• /
• v.16 no.9
• /
• pp.23-32
• /
• 2015

This study examined blast testing measurement data which had been obtained from 97 field sites in Korea to investigate the comprehensive characteristics of rock blasting-induced vibration focusing on the effect of excavation types (tunnel, bench) and rock types. The measurement data was from the testing sites mostly in Kangwon province and Kyungsang province and rock types were granite, gneiss, limestone, sand stone, and shale in the order of number of data. The study indicated that the blasting-induced vibration velocity was affected by the excavation types (tunnel, bench) and bench blasting induced higher velocity than tunnel blasting. In addition, the vibration velocity was also highly affected by the rock types and therefore, it can be concluded that rock types should be considered in the future to estimate a blasting-induced vibration velocity. Furthermore, the pre-existing criteria was compared with the results of this study and the comparison indicated that there was a discernable difference except for tunnel blasting results based on the square root scaling and therefore, further studies and interests, which include the effects of rock strength, joint characteristics, geological formation, excavation type, power type, measurement equipment and method, might be necessarily in relation to the estimation of blasting-induced vibration velocity in rock mass.