• Journal of the Computational Structural Engineering Institute of Korea
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• v.30 no.5
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• pp.435-444
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• 2017

The vehicle-track structure dynamic interaction analysis problem can be treated as sliding contact problem, and it is assumed that vehicle run at a constant speed over a rail modeled as beam elements. Unfortunately, Salome-Meca can not satisfy the compatibility condition for the beam master elements, which are consist of the elements with higher order polynomial shape function, in sliding contact problem. In this study, it is suggested to use more finer beam master element mesh as the remedy for incompatibility in sliding contact problem, and the accuracy of the solution is secured. For this, the effect of beam element mesh refinement consisting runway is analysed through simple examples, and the applicability to the dynamic interaction analysis is evaluated. Finally, the dynamic interaction analysis of railway skewed culvert transition problem is carried out to evaluate the effect of supporting stiffness due to backfill pattern changes and track irregularity due to uneven subgrade settlement.

• Journal of the Korean Magnetics Society
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• v.11 no.5
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• pp.189-195
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• 2001

We prepared TMR junctions of NiFe(170 )/CoFe(48 )/Al(13 )-O/CoFe(500 )/Ta(50 ) structure on 2.5$\times$2.5 $\textrm{cm}^2$ area Si/SiO$_2$ substrates in order to investigate the uniformity of magnetoresistance(MR) value using a ICP magnetron sputter. Each layer was deposited by the ICP magnetron sputter and tunnel barrier was formed by the plasma oxidation method. We measured MR ratio and resistance of TMR devices with four-terminal probe system by applying external magnetic field. Although we used ICP sputter which is known as superior to make uniform films, the standard variation of MR ratio was 2.72. The variation was not dependent on the TMR devices location of a substrate. We found that MR ratio and spin-flip field (H's) increased as the resistance increased, which may be caused by local interface irregularity of the insulating layer. The variation of resistance value was 64.19 and MR ratio was 2.72, respectively. Our results imply that to improve the insulating layer fabrication process including annealing process to lessen interface modulation in order to mass produce the TMR devices.

• The Korean Journal of Food And Nutrition
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• v.9 no.4
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• pp.441-446
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• 1996

This study chosed the 3 groups(lean type(41), the normal type(48) and the obese type(58)) according the BMI and then by comparing the nutrition intake and eating behaviors of each 3 groups. The results obtained were summarized as follows: A significantly difference of nutrition-intake in 3 groups is shown in the take daily food-intake and calorie-intake of snack, which the obese type intakes of protein most, the normal type that intakes of calcium most. The food-habit shown in the self report of each subject, is the irregularity of the food-eating in all 3 groups. In terms of self-estimation by actual physique, the obese type estimates mostly correctly his own physique. To compared self-estimation of eating behaviors, The estimation of the unbalanced deities mostly correct.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39B no.5
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• pp.281-290
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• 2014

The real-time data dissemination schemes exploit the spatiotemporal commuication approach which forwards data at the delivery speed calculated with the desired time deadline and the end-to-end distance in wireless sensor networks (WSNs). In practical environments, however, the performance of the real-time data dissemination might be degraded by additional and inevitable delay due to some holes. Namely, the holes lengthen the data delivery path and the spatiotemporal approach could not estimate a distance of the data delivery path. To deal with this, we propose A Hole Self-Organization Real-time Routing Protocol for Irregular Wireless Sensor Networks. In proposed protocol, nodes around holes could detect them at deploying phase. A hole is represented as a circle with center point and radius. This hole information is processed and provided as a form of location service. When a source queries a destination location, location provider replies certain points for avoiding holes as well as destination location. Thus, the source could set desired speed toward the destination via the points. Performance evaluation shows that provides better real-time service in practical environments.

• Journal of the Earthquake Engineering Society of Korea
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• v.13 no.1
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• pp.35-43
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• 2009

Two types of piloti-type high-rise RC building structures having irregularity in the lower two stories were selected as prototypes, and nonlinear time history analysis was performed using OpenSees to verify the analysis technique and to investigate the seismic capacity of those buildings. One of the buildings studied had a symmetrical moment-resisting frame (BF), while the other had an infilled shear wall in only one of the exterior frames (ESW). A fiber model, consisting of concrete and reinforcing bar represented from the stress-strain relationship, was adapted and used to simulate the nonlinearity of members, and MVLEM (Multi Vertical Linear Element Model) was used to simulate the behavior of the wall. The analytical results simulate the behavior of piloti-type high-rise RC building structures well, including the stiffness and yield force of piloti stories, the rocking behavior of the upper structure and the variation of the axial stiffness of the column due to variation in loading condition. However, MVLEM has a limitation in simulating the abrupt increasing lateral stiffness of a wall, due to the torsional mode behavior of the building. The design force obtained from a nonlinear time history analysis was shown to be about $20{\sim}30%$ smaller than that obtained in the experiment. For this reason, further research is required to match the analytical results with real structures, in order to use nonlinear time history analysis in designing a piloti-type high-rise RC building.

• Physical Therapy Korea
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• v.3 no.3
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• pp.67-81
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• 1996

This study was performed to assess the efficacy of high voltage pulsed galvanic current for the healing of wounds in rabbits. Skin wounds were created laterally on the flank of 12 domestic rabbits($3{\times}3cm$). The wounds of each group were treated with an intensity of 170 V at a frequency of 70 pulses per second, which was applied for 30 minutes a day for 10 days. The experimental groups were randomly assigned to either EXP I (n=3), EXP II(n=3), EXP III(n=3) or control(n=3). Each group was stimulated under the following conditions : 1) EXP I (Negative polarity), 2) EXP II (Change in polarity, negative electrode stimulation during the first 3 days and then positive electrode stimulation from 4 to 10 days), 3) EXP III(Positive polarity), 4) control(No stimulation). An active electrode was placed over the wound and a dispersive electrode on the buttock. The rate of wound closure was compared with the original wound size, evaluated by a tracing film in each measurement period. Finally, on the wound in each group, skin tissue was excised for histological evaluation after treatment for 10 days. The results obtained are as follows : 1) It was found that the control group did not show a complete remodeling of epitherial layer and had a chronic inflammatory response. Judging from the irregularity of intercellular space and the loose alignment of connective tissue, these findings show that wound healing was delayed. 2) EXP I showed a significant bactericidal effect, but a moderate response of vasodilation. The rate of wound closure was slower when compared with EXP II, III. 3) EXP II showed a complete remodeling of epitherial layer and a positive repair of connective tissue. Its rate of wound closure was best when compared with the others. 4) EXP III had a slower rate of wound closure than EXP II, but judging from the greater proliferation of collagen fibers and the dense alignment of connective tissue, this positive electrode was very effective in the formation of neo - connective tissue.

• Journal of Korean Academy of Nursing
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• v.7 no.1
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• pp.30-38
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• 1977

Breast cancer is one of the most feared health problems in women ; Recent studies revealed that it had come up to be the second most in this country and high prevalent disease in the western countries among breast disease in women. However, early detection of the cancer mass is known to be easier than in many other malignancies. This study was performed to investigate the various characteristics of patients of breast cancer ; by the structural variables, menstrual, marital, and child bearing, and also their understandings and attitude towards the disease. A hundred any in- and out- patients of 51. Mary's Hospital and National Atomic Institute, Seoul were sampled. Data were gathered through direct interview by the researcher from February 1976 to January 1977 and the clinical records were used as references. Results are as follows ; 1. Breast cancer revealed to be most prevalent in the forties ; average age of 45.2 years. 2. The average age of menarche revealed to be 15.4 years ; the largest group were the 16-20 years (N=75, 68.2%). In 55 cases (50%) menstruation were normal, 38 (34.5%) postmenopausal and only in 17 (15.5%), menstruation revealed irregularity. 3. The average marital age revealed to be 22.3 years ; the largest group were 21-25 group (N=43, 39.1%). The average duration of marital life revealed to be 24.7 years ; 11-20 years group were the largest (M=34, 30.9%). 4. Most of the patients revealed to have pregnancy experiences(N=100, 90.9%) ; the average rate of experience were 5, 3 times the largest group were 3.4 times group(N= 32, 29.1%). 54 patients (49.1%) revealed to have had abortion experience ; the average were 3.4 times. 5. The largest group(N=77, 70%) had been breast feeding : followed by mixed feeding (N=12, 10.9%) and artificial feeding(N=10, 9.1%). 6. Personal health history revealed that in 20 patients (18.2%) revealed to have the past history of Purulent mastitis, 5 patients(4.5%) of breast cancer and 3 patients(2.7%) of uttering cancer family history. 7. In the one half (N=56, 50.9%, they had some information about breast cancer :27 (24.5%) by mass media, 12 (10.9%) through personal contacts and 17 (15.5%) were not able to classify the source of information. 8. In 55 cases (50%) the canoe, mass were discovered incidentally, in 39 cases (35.5%) by manual detection by self, in 10 cases (9%) by others and in 6 cases(5.5%) by observing subjective symptoms. 9. The average duration lapsed between the discovery of cancer mass and the visit to the hospital revealed to be 9.4 month. Chief reason for the delay revealed to be the non-chaplaincy due to the absence of pain(N=50, 45.5 %) followed by the administration of herb and commercial medication (N=19, 17.3%). 10. The left side breast was more affected than the right side breast, represent by 60 cases in the left and 39 cases in the right. The most frequent site of the breast cancer was the upper- outer quadrant in 53 cases (47.7%), and followed by the center in 20 cases(18 %), and the upper inner quadrant, in 19 cases (17.1%). There was / cases of bilateral carcinoma. The most prominent symptom was painless mass.

• Journal of Periodontal and Implant Science
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• v.35 no.4
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• pp.921-937
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• 2005

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- HCl on the change of implant surface microstructure according to application time. Implants with pure titanium machined surface, SLA surface and $TiO_2blasted$ surface were used in this study. Implant surface was rubbed with sponge soaked in 50mg/ml tetracycline - HCl solution for $\frac{1}{2}$ min., 1min., $1\frac{1}{2}$ min., 2 min., and $2\frac{1}{2}min.$ respectively in the test group and with no treatment in the control group. The sponge was soaked in every 30 seconds. Then, the specimens were processed for scanning electron microscopic observation. Based upon the analysis of photographs by three dentists who are not related with this study, the results were obtained as follows; 1. In the pure titanium machined surfaces, the control specimen showed a more or less rough machined surface composed of alternating positive and negative lines corresponding to grooves and ridges. After treatment, machining line was more pronounced for the control specimens. but in general, test specimens were similar to control. 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 tetracycline - HCl solution, in general, test specimens were similar to control. 3. In the $TiO_2blasted$ surfaces, the control specimen showed the rough surface With small pits. The irregularity of the $TiO_2blasted$ surfaces with 50mg/ml tetracycline - HCl solution was lessened and the flattened areas got wider after 1 minute.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.2
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• pp.192-200
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• 2006

The aim of this study was to assess the microleakage underneath a pit and fissure sealant bonded to occlusal surfaces treated by Er:YAG laser To determine the most effective energy density of laser, fourteen specimens were irradiated from 50mJ to 300mJ at 3Hz. After irradiation, the lased specimens were observed under the scanning electron microscope. Thirty six non-carious extracted premolars were randomly assigned to four groups of nine teeth: group 1, no treatment on the occlusal surface; group 2, acid etching for 15 seconds; group 3, Er:YAG laser irradiation; group 4, acid etching followed by Er:YAG laser irradiation. The pits and fissures were sealed with unfilled sealant(Helioseal F) and the specimen teeth were thermo-cycled, immersed in 2% Rhodamine B solution, longitudinally sectioned and analyzed for microleakage with fluorescent microscope. The results were as follows: 1. Er:YAG lased surfaces with 50mJ, 3Hz showed a similar pattern of irregularity with acid etched enamel surfaces 2. The mean microleakage score increased in the order of group 2, 4, 3 and 1. There was no significant difference among group 1, 3 and 4(p>0.05), however group 2 showed significantly less microleakage compared with group 1 and 3. Conclusively, the laser irradiation seemed not enough to replace the acid etching for proper retention of pit and fissure sealants.

• Journal of the East Asian Society of Dietary Life
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• v.18 no.5
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• pp.662-674
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• 2008

The purpose of this study was to investigate the patterns of fast food intake in residential areas and its relation to eating habits among 551 6th grade students (286 male students and 265 female students) from elementary schools located in Gangnam-gu, Dongjak-gu and Seongbuk-gu, Seoul. The results of this study were as follows. 1) There were significant differences in the preference for fast food among districts (p<0.05) and children from Seongbuk-gu showed a greater preference for fast food than those from Gangnam-gu and Dongjak-gu. In terms of preferences for particular types of fast food, children from Seongbuk-gu liked hamburgers more than those from Gangnam-gu and Dongjak-gu so that there were significant differences among districts (p<0.05). With regards to the frequency of intake of the various types of fast food, there were differences in hamburger, pizza and chicken among three districts (p<0.05) and children from Seongbuk-gu ate fast food 1 to significant 2 times more often than those from Gangnam-gu and Dongjak-gu. 2) There were significant differences in the regularity of mealtimes between districts (p<0.05), with children from Seongbuk-gu showing more irregularity in their mealtimes than those from Gangnam-gu and Dongjak-gu. There were significant differences in the frequency of snack intake (p<0.05), and children from Seongbuk-gu tended to take a snack 1 to 2 times more often than those from Gangnam-gu and Dongjak-gu. 3) In the frequency of fast food intake in accordance with obesity, there were significant differences between the obesity index (p<0.05). In particular, children who were underweight had a tendency to eat more fast food. There were significant differences between the frequency of fast food intake depending on children's pocket money (p<0.05), and children who took fast food more than twice a week tended to have more pocket money. According to these results, we report there are partly different trends in the consumption of fast food and food habits among the districts in Seoul. Therefore we suggest that different interventions be implemented within the different districts to reduce reliance on fast food restaurants and to address the perceptions of healthy eating as well as time and convenience barriers.