• Journal of Dental Anesthesia and Pain Medicine
• /
• v.17 no.4
• /
• pp.281-287
• /
• 2017

Background: Various techniques have been introduced to decrease complications during nasotracheal intubation. A common practice is to use nasal packing with a cotton stick and 0.01% epinephrine jelly. However, this procedure can be painful to patients and can damage the nasal mucosa. Xylometazoline spray can induce effective vasoconstriction of the nasal mucosa without direct nasal trauma. In this study, we aimed to compare the efficacy of these two methods. Methods: Patients were randomly allocated into two groups (n = 40 each): xylometazoline spray group or epinephrine packing group. After the induction of general anesthesia, patients allocated to the xylometazoline spray group were treated with xylometazoline spray to induce nasal cavity mucosa vasoconstriction, and the epinephrine packing group was treated with nasal packing with two cotton sticks and 0.01% epinephrine jelly. The number of attempts to insert the endotracheal tube into the nasopharynx, the degree of difficulty during insertion, and bleeding during bronchoscopy were recorded. An anesthesiologist, blinded to the intubation method, estimated the severity of epistaxis 5 min after intubation and postoperative complications. Results: No significant intergroup difference was observed in navigability (P = 0.465). The xylometazoline spray group showed significantly less epistaxis during intubation (P = 0.02). However, no differences were observed in epistaxis 5 min after intubation or postoperative epistaxis (P = 0.201). No inter-group differences were observed in complications related to nasal intubation and nasal pain. Conclusion: Xylometazoline spray is a good alternative to nasal packing for nasal preparation before nasotracheal intubation.

• Smart Structures and Systems
• /
• v.19 no.1
• /
• pp.57-66
• /
• 2017

Nanocomposites reinforced with carbon nanotube fibers exhibit greater stiffness, strength and damping properties in comparison to conventional composites reinforced with carbon/glass fibers. Consequently, most of the nanocomposite research is focused in understanding the dynamic characteristics, which are highly useful in applications such as vibration control and energy harvesting. It has been observed that those nanocomposites show better stiffness when the geometry of nanotubes is straight as compared to curvilinear although nanotube agglomeration may exist. In this work the damping behavior of the nanocomposite is characterized in terms of loss factor under the presence of nanotube agglomerations. A micro stick-slip damping model is used to compute the damping properties of the nanocomposites with multiwall carbon nanotubes. The present formulation considers the slippage between the interface of the matrix and the nanotubes as well as the slippage between the interlayers in the nanotubes. The nanotube agglomerations model is also presented. Results are computed based on the loss factor expressed in terms of strain amplitude and nanotube agglomerations. The results show that although-among the various factors such as the material properties (moduli of nanotubes and polymer matrix) and the geometric properties (number of nanotubes, volume fraction of nanotubes, and critical interfacial shear stresses), the agglomeration of nanotubes significantly influences the damping properties of the nanocomposites. Therefore the full potential of nanocomposites to be used for damping applications needs to be analyzed under the influence of nanotube agglomerations.

• Journal of Oral Medicine and Pain
• /
• v.36 no.4
• /
• pp.215-224
• /
• 2011

The aim of the study was to investigate the effects of 904 nm GaAs laser irradiation for patients with hypersensitive teeth and to find the possibility of clinical use of this Low Level Laser Therapy (LLLT) for the control of hypersensitive teeth. Eleven patients visited Dept. of Oral Medicine, Dankook University participated in this study. Each patient contributed at least two or more contralateral pairs of hypersensitive teeth with exposed dentine at cervical surfaces. Total number of teeth used from subjects participated in this study was 50: 25 experimental and control teeth respectively. All participants were treated with 904 nm GaAs diode laser every week during 4 weeks. Tactile and cold (ice stick) tests were carried out before LLLT every week during 4 weeks and 1 week later after the last LLLT by measuring visual analogue scale (VAS) of patients and by measuring a score of electrical pulp tester (EPT) simultaneously. The VAS score in tactile test decreased significantly with time, but there was not statistically difference between those of groups. The score of EPT in the experimental group was significantly higher than that of control group, although there was no change with time. In cold test, there was significant difference between two groups and cold sensitivity of the experimental group significantly decreased with time after every LLL irradiation, compared with that of control group. Based on the results, it is suggested that the 904 nm GaAs laser irradiation could be positively used as an effective, reversible method in treating cervical dentine hypersensitivity.

• Structural Engineering and Mechanics
• /
• v.54 no.1
• /
• pp.169-188
• /
• 2015

This study presents the effects of the spatial variation of ground motions in a hard rock site on the seismic responses of a base-isolated nuclear power plant (BI-NPP). Three structural models were studied for the BI-NPP supported by different number of lead rubber bearing (LRB) base isolators with different base mat dimensions. The seismic responses of the BI-NPP were analyzed and investigated under the uniform and spatial varying excitation of El Centro ground motion. In addition, the rotational degrees of freedom (DOFs) of the base mat nodes were taken to consider the flexural behavior of the base mat on the seismic responses under both uniform and spatial varying excitation. Finally, the seismic response results for all the analysis cases of the BI-NPP were investigated in terms of the vibration periods and mode shapes, lateral displacements, and base shear forces. The analysis results indicate that: (1) considering the flexural behavior of the base mat has a negligible effect on the lateral displacements of base isolators regardless of the number of the isolators or the type of excitation used; (2) considering the spatial variation of ground motions has a substantial influence on the lateral displacements of base isolators and the NPP stick model; (3) the ground motion spatial variation effect is more prominent on lateral displacements than base shear forces, particularly with increasing numbers of base isolators and neglecting flexural behavior of the base mat.

• The Korean Journal of Community Living Science
• /
• v.23 no.1
• /
• pp.17-30
• /
• 2012

This study is targeted on children's parks in Seogu, Daejeon with the goal of maximizing the usage and versatility of existing parks in the area by the survey and analysis of the general status of children's parks, land use near the parks, population, users, and traits of usage. For the purposes of this thesis this study has selected 65 of the children's parks in the Seogu District to monitor. It also focused on a number of these parks located in areas which underwent a lot of changes and needed an increase in usage and versatility. Based on the selection criteria, the four target parks, Wojeong, Meongwhack, Dosan and Wicdunjimi children's park were selected. The Survey shows that 55.9% of park visitors visited a park to 'rest and take a walk' and used 'main facilities' meaning resting facilities like pergola and benches. In the nighttime, the number of park visitors is so few because of safety problems. 50% of users were satisfied with parks. It shows that there are many respondents who want to recompose these parks as places for light exercise, resting, meeting, and as community symbols. Generally, these target parks don't reach their full potential and they also do not play their proper roles because they are hampered by the constriction of the law. These stick to an outdated idea of what a park should be like without considering the actual and practical needs of city dwellers. When it comes to the remodeling and refurbishing of these parks we have to rethink the planning process so that these parks may be more versatile and practical in order to accommodate the radical changes of users and patterns of usage.

• Tribology and Lubricants
• /
• v.23 no.5
• /
• pp.219-227
• /
• 2007

The dynamic performance of air foil bearings relies on a coupling between a thin air film and an elastic foil structure. A number of successful analytical techniques to predict dynamic performance have been developed. However, the evaluation of its dynamic characteristic is still not enough because of the mechanical complexity of the foil structure and strong nonlinear behavior of friction force. This work presents a nonlinear transient analysis method to predict dynamic performance of foil bearings. In this method, time dependent Reynolds equation is used to calculate pressure distribution and a finite element method is used to model the bump foil structure. The analysis is treated with a direct implicit integration technique that can handle nonlinear problems and the stick-slip algorithm is used to consider friction force. Using this method the response to the mass unbalance excitation is investigated for various design parameters and operating conditions. The results of analysis show that foil bearing is very effective on the restriction of vibration at the resonance frequency compared to the rigid surface bearings and the effectiveness depends on the operating conditions, static load and a amount of mass unbalance. In addition, there exist optimum values of friction coefficient, bump foil stiffness and number of circumferential slit with regards to minimizing dynamic response at the resonance frequency. These optimum values are system dependent.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.40 no.2
• /
• pp.97-103
• /
• 2004

This paper presents a general overview of the Korean stick-held dip net fishery for Pacific saury operated in the North Pacific Ocean since 1985. Annual catches, annual centroids distribution of fishing ground, and optimum fishing temperatures were compared between the periods before and after the new Korea-Japan bilateral fishery arrangement established in 1998. Fishing usually began in May and ended by December, during which major catches were taken in the months September~November before the bilateral fishery arrangement between Korea and Japan, whereas in August~October after the arrangement. It was observed that after the arrangement the centroids of fishing ground was shifted from the usual fishing area off the east coast of Japan to the east of South Kuril Islands, 45$^{\circ}$N and 151$^{\circ}$E. Optimum fishing temperatures appeared to be different by month ; 12.5~14.4$^{\circ}C$ in May, 12.0~14.2$^{\circ}C$ in June, 11.4~13.9$^{\circ}C$ in July, 11.4~15.9$^{\circ}C$ in August, 12.9~16.9$^{\circ}C$ in September, 12.7~17.3$^{\circ}C$ in October, 13.1~17.6$^{\circ}C$ in November, and 15.0~19.1$^{\circ}C$ in December. A total of 13 species were caught during scientific observation periods but the target species, Pacific saury, accounted for about 99.9% of the total catch. Although there was no difference in fishing days between those vessels equipped with the sonar and those without sonar, number of set, total catch, and CPUE of those with sonar were higher than those without sonar by 13%, 26%, and 12%, respectively.

• (The) Research of the performance art and culture
• /
• no.37
• /
• pp.5-31
• /
• 2018

The mask dance drama Goseong Ogwangdae's first act, Mundung Bukchum. The story is about a man who was born to the upper class but contracted leprosy, an incurable disease, due to his ancestors' accumulated sin. Although he is suffering, he is able to triumph over the disease through sinmyeong (catharsis) that is expressed through the wordless act of Mundung Bukchum. This thesis focuses on Goseong Ogwangdae's Mundung Bukchum, particularly the meaning, costume, accompanying music, and process of pedagogical transmission. The chronological characteristics of Goseong Ogwangdae's Mundung Bukchum are as follows. First, as time goes on, the number of dance motions in Mundung Bukchum has increased and the motions used have become reified. Second, I address the small barrel drum used in Mundung Bukchum and check how, through the drum, the changed expression of Mundung is shown.In a 1965 video introduced Mundung is grasping the drum and stick and the dance appears to be made up only of humorous motions. Also in a 1969 video, "Mundung Gwangdae," from the start Mundung is grasping the drum and stick. In 1988 in a video we can see the same scene as today, with the drum and stick sitting in the center of the stage at the start of the dance. We can also confirm that the same fourteen dance motions used today are present. Third, we can also confirm the changes in Goseong Ogwangdae's signature motion, baegimsae as time goes on. Observing the video from 1965, baegimsae does not appear in Mundung Bukchum. In 2000 we can clearly see the baegimsae performed once to the left and to the right while Mundung is squatting. Comparing 1969 to 1988, there is no symmetry in the motions, baegimsae is not done to both left and right, but only in one direction. Watching the record from 2000, the baegimsae motion is performed just as it is now, with the body thrown forward with a sharp push off the ground. Fourth I confirmed how the music used to accompany Goseong Ogwangdae's Mundung Bukchum has changed over time. In 1965 according to records of Mundung Bukchum's appearance, the dance was accompanied by the taryeong rhythmic pattern played on the usual four percussion instruments (barrel drum, hourglass drum, large gong, small gong). In the 1969 records of Mundung Bukchum the accompanying music is gutgeori rhythmic pattern performed on the usual four percussion instruments-an obvious difference. In 1988 the music with Mundung Bukchum is gutgeori rhythmic pattern transitioning into jajinmori rhythmic pattern. In 2000 the music with Mundung Bukchum includes the percussion instruments as well as taepyeongso (double reed oboe) playing gutgeori and jajinmori rhythmic patterns.

• Quality Improvement in Health Care
• /
• v.10 no.2
• /
• pp.190-203
• /
• 2003

Background: Dental hygienists are at risk of acquiring infections through exposure to infectious agents. This study explores the frequency of exposure to infectious agents and infection control practices among dental hygienists. Methods: We undertook a cross-sectional survey to examine the exposure to infectious agents and infection control practices among dental hygienists through questionnaire. Data were obtained from 124 dental hygienists attending educational conferences. A multiple logistic regression analysis was conducted to determine the factors that effect infection control practices in relation to age, completion of infection control education, recognition of their own serum hepatitis Ag/Ab status, the number of one day patients, location of clinics, type of clinics, and career years. Result: Of the 124 dental hygienists, 91.7% were exposed to at least one accident such as needle stick injuries during their practices periods. The health screening coverage rate in dental hygienists was 16.5%. The number of one day patients and career years were important in relation to infection control practices among dental hygienists. The adjusted odds ratio estimates for career years were 5.049 times greater(95% Cl 1.238-20.597) for groups with over 4 career years than under 2 career years. That for the number of one day patients were 0.261(95% Cl 0.071-0.955) lower for through 20 up to 30 patients, 0.531(95% Cl 0.102-2.78) lower for through 30 up to 40 patients and 0.498(95% Cl 0.123-2.017) lower for more than 40 patients than under 20 patients. Conclusion: From these results, prevalence of infection control practices among dental hygienists is related to the number of one day patients and career years. Prevention of cross infection and reduction of future transmission should be a priority to dental hygienists for promotion of infection control and further efforts to educate newcomers on infection prevention should be made.

• The Korean Journal of Pesticide Science
• /
• v.17 no.4
• /
• pp.440-447
• /
• 2013

F. occidentalis (WFT, western flower thrips) is a major pest in artificial chrysanthemum houses. Nnumber of WFT attracted to yellow sticky trap was highest at trap plant and lowest at 15 and 20m places away from trap plant. Number of WFT attracted to yellow stick trap when trap plant was placed in chrysanthemum house 30 days after planting (resident WFT) was 4.4~7.7 times more than at 5 and 10 m places away from trap plant and when trap plant was placed in chrysanthemum house immediately after planting (resident WFT) was 5.7~9.4 times more at 5 and 10 m places away from trap plant. Number of WFT between the place trap plant located and unlocated was undifferent when cultured chrysanthemum formed flower. In case of the plot that trap plant and natural enemy was used simultaneously, number of WFT was highter then chemicals plot. In case of the plot that trap plant and chamicals (chemicals was sprayed on trap plant only) WFT was controlled in trap plant place only but density of WFT on 5m and 10m places away from trap plant was increased. Therefore, WFT could be controlled effectively by use of trap plant (flowering yellow chrysanthemum) and natural enemy simultaneously.