• Journal of dental hygiene science
• /
• v.9 no.3
• /
• pp.319-326
• /
• 2009

The purpose of this study was to examine the Influence of the experience of Childcare Teacher about oral health education on oral health behaviors. For this, Questionnairs to be self-filled up about experience of oral health education were carried out to 267 childcare teachers who are working in nurseries in Geongnam province. The date was analysed using the SPSS 12.0 program. The obtained result were as follows. Among the respondents who are not under stress of oral health. 8.1% respondents had the oral health education and 7.7% others didn't have it. For toothbrushing methods, it was found that 25.3% used manual toothbrushing with experience in dental education(up and down toothbrushing monement) and 35.4% used semi automatic toothbrushing(rotational movement). 37.1% respondents had experiences in oral health education, 69.7% respondents were instructed in the oral health at public health center, and 61.6% respondents were instructed in the oral health a theory(toothbrushing guidance). Among the respondents who answered that oral health education should be necessary, 83.4% of those have already had oral health education where as 73.8% respondents have not had the education. 67.7% of the respondents who want to participate in the oral health education is corresponding to those with experience in dental education, 66.1% respondents with no education feel the necessity of the oral health education.

• Journal of the Korean Society of Radiology
• /
• v.12 no.5
• /
• pp.583-592
• /
• 2018

In this study, plans to apply 3D conformal radiotherapy, intensity modulated radiotherapy, and volumetric intensity modulated arc radiotherapy to esophageal cancer radiotherapy were compared. In particular, arc therapy was applied to reduce irradiated volume and spread of low-dose during intensity modulated radiation therapy and volumetric intensity modulated arc radiotherapy by limiting part of irradiated angle, in order to compare target doses and dose for surrounding normal tissues of the two methods and those of 3D conformal radiotherapy. No significant difference in target dose was found among the three methods. The 5 Gy volume(V5) of the lung showed 56.53% of conformal radiotherapy, 52.03% of intensity modulated radiotherapy, and 47.84% of volumetric modulated arc therapy(CRT-IMRT p=0.035, CRT-VMAT p<0.001, IMRT-VMAT p<0.001). The 10 Gy volume(V10) showed a significant difference in conformal radiotherapy 35.12%, intensity modulated radiotherapy 34.04%, and volumetric modulated arc radiotherapy 33.28%, showing significant difference in intensity modulated radiotherapy(p=0.018), volumetric modulated arc therapy(p=0.035), no significant difference in dose was found at 20 Gy volume. The mean dose and 20 Gy volume of the heart were not significantly different according to the treatment plan, but the 30 and 40 Gy volumes were 37.16% and 22.46% in the volumetric modulated arc radiotherapy, showing significant differences(p=0.028) in comparison with conformal radiotherapy. It is believed that, by limiting part of the irradiated angle during intensity modulated radiotherapy and volumetric intensity modulated arc radiotherapy, the irradiated volume and, thereby, the 5-10 Gy area and toxicity of the lung can be reduced while maintaining dose distribution of the target dose.

• International Journal of Ocean System Engineering
• /
• v.2 no.3
• /
• pp.185-194
• /
• 2012

A Macroscopic combination of two or more distinct materials is commonly referred to as a "Composite Material", having been designed mechanically and chemically superior in function and characteristic than its individual constituent materials. Composite materials are used not only for aerospace and military, but also heavily used in boat/ship building and general composite industries which we are seeing increasingly more. Regardless of the various applications for composite materials, the industry is still limited and requires better fabrication technology and methodology in order to expand and grow. An example of this is that the majority of fabrication facilities nearby still use an antiquated wet lay-up process where fabrication still requires manual hand labor in a 3D environment impeding productivity of composite product design advancement. As an expert in the advanced composites field, I have developed fabrication skills with the use of machinery based on my past composite experience. In autumn 2011, the Korea government confirmed to fund my project. It is the development of a composite sanding machine. I began development of this semi-robotic prototype beginning in 2009. It has possibilities of replacing or augmenting the exhaustive and difficult jobs performed by human hands, such as sanding, grinding, blasting, and polishing in most often, very awkward conditions, and is also will boost productivity, improve surface quality, cut abrasive costs, eliminate vibration injuries, and protect workers from exposure to dust and airborne contamination. Ease of control and operation of the equipment in or outside of the sanding room is a key benefit to end-users. It will prove to be much more economical than normal robotics and minimize errors that commonly occur in factories. The key components and their technologies are a 360 degree rotational shoulder and a wrist that is controlled under PLC controller and joystick manual mode. Development on both of the key modules is complete and are now operational. The Korean government fund boosted my development and I expect to complete full scale development no later than 3rd quarter 2012. Even with the advantages of composite materials, there is still the need to repair or to maintain composite products with a higher level of technology. I have learned many composite repair skills on composite airframe since many composite fabrication skills including repair, requires training for non aerospace applications. The wind energy market is now requiring much larger blades in order to generate more electrical energy for wind farms. One single blade is commonly 50 meters or longer now. When a wind blade becomes damaged from external forces, on-site repair is required on the columns even under strong wind and freezing temperature conditions. In order to correctly obtain polymerization, the repair must be performed on the damaged area within a very limited time. The use of pre-impregnated glass fabric and heating silicone pad and a hot bonder acting precise heating control are surely required.

• The Journal of Korean Society for Radiation Therapy
• /
• v.21 no.2
• /
• pp.83-88
• /
• 2009

Purpose: Cone beam computed tomography (CBCT) using an on board imager (OBI) can check the movement and setup error in patient position and target volume by comparing with the image of computer simulation treatment in real.time during patient treatment. Thus, this study purposed to check the change and movement of patient position and target volume using CBCT in IMRT and calculate difference from the treatment plan, and then to correct the position using an automated match system and to test the accuracy of position correction using an electronic portal imaging device (EPID) and examine the usefulness of CBCT in IMRT and the accuracy of the automatic match system. Materials and Methods: The subjects of this study were 3 head and neck patients and 1 pelvis patient sampled from IMRT patients treated in our hospital. In order to investigate the movement of treatment position and resultant displacement of irradiated volume, we took CBCT using OBI mounted on the linear accelerator. Before each IMRT treatment, we took CBCT and checked difference from the treatment plan by coordinate by comparing it with the image of CT simulation. Then, we made correction through the automatic match system of 3D/3D match to match the treatment plan, and verified and evaluated using electronic portal imaging device. Results: When CBCT was compared with the image of CT simulation before treatment, the average difference by coordinate in the head and neck was 0.99 mm vertically, 1.14 mm longitudinally, 4.91 mm laterally, and 1.07o in the rotational direction, showing somewhat insignificant differences by part. In testing after correction, when the image from the electronic portal imaging device was compared with DRR image, it was found that correction had been made accurately with error less than 0.5 mm. Conclusion: By comparing a CBCT image before treatment with a 3D image reconstructed into a volume instead of a 2D image for the patient's setup error and change in the position of the organs and the target, we could measure and correct the change of position and target volume and treat more accurately, and could calculate and compare the errors. The results of this study show that CBCT was useful to deliver accurate treatment according to the treatment plan and to increase the reproducibility of repeated treatment, and satisfactory results were obtained. Accuracy enhanced through CBCT is highly required in IMRT, in which the shape of the target volume is complex and the change of dose distribution is radical. In addition, further research is required on the criteria for match focus by treatment site and treatment purpose.

• Clinics in Shoulder and Elbow
• /
• v.15 no.2
• /
• pp.79-85
• /
• 2012

Objective: It has been expected that patient with posttraumatic recurrent anterior shoulder dislocation might have limited daily life activity because of pain and apprehension of dislocation. But there have been only a small number of investigations regarding the rotator strength in this patient. The aim of this study is to find the characteristics about rotator strength of patient with posttraumatic recurrent anterior shoulder dislocation using an isokinetic testing. Method: We enrolled thirteen patients with posttraumatic recurrent anterior shoulder dislocation and fifteen sex, age-matched healthy nonathletic subjects in this controlled study. All participants were male and there were no significant differences between the two groups in age, height, weight, BMI. Isokinetic internal rotator and external rotator strength was evaluated with a Biodex Isokinetic Testing machine (Biodex Medical Systems, Shirley, NY, USA), tests were performed at 60 deg/sec and 180 deg/sec for both sides. Peak torque normalized to body weight, external rotator to internal rotator ratio, total work and fatigue were calculated for each angular velocity. The association between internal rotator and external rotator strength and shoulder instability was analyzed by comparisons with a control group. Results: Any notable differences could not be found between the two groups given all data from no symptomatic left shoulder. There were no significant differences between the two groups statistically in internal rotation strength of right shoulder. However, there has been a tendency that at all angular velocities, external rotator peak torque to body weight, total work and external rotator to internal rotator ratio were significantly lower in the anterior instability group than the control group at all angular velocities. There was no substantial difference between those groups with respect to the fatigue of external rotator and internal rotator in our study. Conclusion: The prominent characteristics of posttraumatic recurrent anterior shoulder dislocation are external rotator weakness and loss of balance with external rotator and internal rotator. Therefore selective training using this information rotator might be helpful in conservative treatment and rehabilitation.

• The korean journal of orthodontics
• /
• v.25 no.5 s.52
• /
• pp.525-541
• /
• 1995

This study was designed to investigate force systems and tooth movements produced by retraction archwire during retraction of four maxillary incisors after the maxillary canine retraction into the maxillary first premolar extraction space using the computer-aided three-dimensional finite element method. A three-dimensional finite element model, consisting of 2248 elements and 3194 nodes, was constructed. The model consisted of maxillary teeth and surrounding periodontal membranes, .022'$\times$.028'-slot brackets, and 5 types of retraction archwires(.019'$\times$.025' stainless steel archwire) modeled using the beam elements. The contact between the wire and the bracket slot was modeled using the gap elements because of the non-linear elastic behaviors of the contact between them. The forces and moments, End displacements produced by retraction archwire were measured at various conditions to investigate the difference according to types of loops, magnitudes of activation force, gable angle, and anterior lingual root torque. The results were expressed quantitative and visual ways in the three-dimensional method. The following conclusions can be drawn from this study.1. When the tear-drop loop archwire was activated, the mesio-distal and lingual translational movements of the teeth helped to close the extraction space, but unwanted movements of the teeth including intrusions and extrusions, and rotational movements in each direction occurred. 2. Activation of T-loop archwire compared with those of other types of retraction archwires produced the least translational movements of the teeth helped to space closure and also the least unwanted movements of the teeth. 3. Increasing amount of activation in the tear-drop archwire led not only to increase of translational movements of the teeth helped to space closure, but also to increase of unwanted movements of the teeth. 4. Addition of gable bend in the tear-drop archwire helped anterior teeth to translational movements in the mesio-distal direction, but increased unwanted movements of the teeth 5. Addition of anterior lingual root torque in the tear-drop archwire helped central and lateral incisor to improve their facio-lingual inclination, but increased unwanted movements of the teeth.

• Journal of the Korean Arthroscopy Society
• /
• v.12 no.1
• /
• pp.18-23
• /
• 2008

Purpose: The purpose of this study is to evaluate the clinical results of the function and stability of ACL reconstruction using the flexible reamer. Materials and Methods: We reviewed 98 patients who taken ACL reconstruction using the flexible reamer from March, 1999 to May, 2004. And the follow-up period was more than 12 months in all cases. We used the subjective tests including Lysholm knee score and 2000 International Knee Documentation Committee(IKDC) subjective knee score, and the objective tests such as anterior drawer test, Lachman test, pivot shift test, and KT-2000 arthrometer to evaluate the clinical results. Results: In the range of motion of the affected knee, the extension deficit more than 5 degree was 8 cases preoperatively and 1 case postoperatively. The flexion deficit more than 5 degree was 12 cases preoperatively and 2 cases postoperatively. The mean Lysholm knee score was 61.3 point(${\pm}3.5$ SD) preoperatively and 87.7 point(${\pm}2.0$ SD) postoperatively. The mean 2000 International Knee Documentation Committee(IKDC) subjective knee score was 49 point(${\pm}3.3$ SD) preoperatively and 84 point (${\pm}2.2$ SD) postoperatively. 93 cases were more than grade II in Lachman test preoperatively and 5 cases postoperatively. 71 cases were more than grade II in pivot shift test preoperatively but 89 cases were negative postoperatively. The mean maximal manual difference by KT-2000 arthrometer was 6.8 mm(${\pm}1.9$ SD) preoperatively and 1.8 mm(${\pm}0.8$ SD) postoperatively. Conclusion: ACL reconstruction using the flexible reamer achieved the ideal isometric point of femur and anatomic graft placement, so we could obtain good results, especially in rotational stability.

• Progress in Medical Physics
• /
• v.22 no.2
• /
• pp.72-78
• /
• 2011

The aim of this study is to evaluate the patient's setup errors in TomoTherapy (Hi-Art II, TomoTherapy, USA) Bodyfix system (Medical Intelligence, Ele-kta, Schwabmuchen, Germany) pressure in the vacuum compression, depending on and were evaluated. Bodyfix immobilization system and vacuum pressure was compression applied to the patients who received Tomotherapy thoracic and abdominal area, 21 patients were selected and TomoTehpay treatment total 477 of MVCT images were obtained. The translational (medial-lateral: ML, anterior-posterior: AP, superior-inferior: SI directions) and rolling were recorded and analyzed statistically. Using Pearson's product-moment coefficient and One-way ANOVA, the degree of correlation depending on the different vacuum pressure levels were statistically analyzed for setup errors from five groups (p<0.05). The largest average and standard deviation of systematic errors were 6.00, 5.95 mm in the AP and SI directions, respectively. The largest average of random errors were 4.72 mm in the SI directions. The correlation coefficients were 0.485, 0.244, and 0.637 for the ML-Roll, AP-Vector, and SI-Vector, respectively. SI-Vector direction showed the best relationship. In the results of the different degree of vacuum pressure in five groups (Pressure range: 30~70 mbar), the setup errors between the ML, SI in both directions and Roll p=0.00 (p<0.05) were shown significant differences. The average errors of SI direction in the vacuum pressure of 40 mbar and 70 mbar group were 4.78 mm and -0.74 mm, respectively. In this study, the correlation between the vacuum pressure and the setup-errors were statistically analyzed. The fact that setup-errors in SI direction is dependent in vacuum pressure considerly setup-errors and movement of interal organs was identified. Finally, setup-errors, and it, based on the movement of internal organs in Bodyfix system we should apply more than 50 mbar vacuum pressure. Based on the results of this study, it is suggested that accuracy of the vacuum pressure and the quantitative analysis of movement of internal organs and the tumor should be studied.

• Publications of The Korean Astronomical Society
• /
• v.34 no.3
• /
• pp.31-40
• /
• 2019

We study the internal structure under the artificial mountain of Heumkyeonggak-nu, a Korean water-powered clock in the early Joseon dynasty. All the puppets on the artificial mountain are driven by the rotational force generated by the water wheel at their designated time. We design a model that work with three parts of the artificial mountain. At the upper part of the artificial mountain to the east, west, north and south, there are four puppets called the Four Mystical Animal Divinity and four ladies called the Jade Lady respectively. The former rotates a quarter every double hour and the latter rings the bell every hour. In the middle part of this mountain is the timekeeping platform with four puppets; the Timekeeping Official (Hour Jack), the Bell-, Drum-, and Gong-Warriors. The Hour Jack controls time with three warriors each hitting his own bell, drum, and gong, respectively. In the plain there are 12 Jade Lady puppets (the lower ladies) combined with 12 Oriental Animal Deity puppets. In his own time a lady doll pops out of the hole and her animal doll gets up. Two hours later, the animal deity lies down and his lady hides in the artificial plain. These puppets are regularly moved by the signal such as iron balls, bumps, levers, and so on. We can use balls and bumps to explain the concept of the Jujeon system. Iron balls were used to manipulate puppets of the timekeeping mechanism in Borugak-nu, another Korean water-powered clock in Joseon dynasty, which was developed earlier than Heumgyeonggak-nu. According to the North Korea's previous study (Choi, 1974), it is obvious that bumps were used in the internal structure of Heumgyeonggak-nu. In 1669, The armillary clock made by Song, I-young was also utilized bumps. Finally we presented mock-ups of three timekeeping systems.

• Journal of Preventive Medicine and Public Health
• /
• v.25 no.4 s.40
• /
• pp.374-385
• /
• 1992

Some circadian rhythms can become disorgnized due to rotating shift work. This lack of organization, termed desynchronization, can produce a group of symptoms such as insomnia, GI disturbance and fatigue among many rotating shift workers. The magnitude of these symptoms are influenced by personal and environmental factors and the patterns of shift work. This study was carried out to investigate the subjective symptoms related to rotational schedules of shift work after personal and environmental factors adjusted. 182 male workers in rapidly rotating shift system and 86 male workers in weekly rotating shift system were conducted the questionnaire on personal factors and subjective sleep, GI and fatigue symptoms. Major findings obtained from this study are as follows: 1. The symptoms of 'feeling tired at work' and 'being irritable' were more frequent in weekly rotating shift workers (P<0.05), and the mean of symptom score was significantly higher in weekly rotating shift workers(P<0.01). 2. According to 6 hours of sleeping which is a definite elevation point of fatigue, there was not a significant difference between two groups in sleeping hours. Among workers in rapidly rotating shift system, the mean of symptom score was significatly higher in workers of less than 6 hours of sleeping(P<0.05), but it was not different among weekly rotating shift workers. 3. The symptoms of GI disturbance were more frequent in weekly rotating shift workers but statistically not significant. 4. The positive rate of mental and physical fatigue symptoms were significantly higher in weekly rotating shift workers(P<0.01) and mental and physical fatigue symptoms were more frequent in them (P<0.01). 5. After the effect of the factors that were significantly different between two groups by $X^2-test$ were controlled, the mean score of sleep disturbance was significantly higher in weekly rotating shift workers (P<0.01) and mental physical fatigue symptoms were more frequent in them (P<0.01). Based on these study results, subjective symptoms were more common in the weekly rotating shift workers. In future, medical examination and laboratory test will be also administered to evaluate a more accurate health outcomes and the review of current shift schedules will be required.