• The Journal of Korean Academy of Prosthodontics
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• v.47 no.1
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• pp.70-81
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• 2009

Statement of problem: The position and length of cantilever influence on the stress distribution of implants, superstructure and bone. In edentulous mandible, implant-supported cantilever prostheses that based 4 or 6 implants between mental foramens has been attempted. Excessive bite force loaded at cantilever prosthesis causes bone resorption and breakage of superstructure prosthesis around posterior implants. To complement the cantilever length of conventional prosthesis, In 1992, (McCartney) introduced "cantilever-rest-implant" and Malo reported "All-on-Four" in 2003. Purpose: Analyze and compare the stress distribution of conventional cantilever prostheses with rest implant and All-on-$Four^{TM}$ implant prostheses. Material and method: The external loads(300 N vertically, 75 N horizontally) are applied to first molar area. The stress value, stress distribution and aspect of stress dispersion are analyzed by three-dimensional finite element analysis program, ANSYS ver. 10.0. Results: 1. The rest implant and "All-on-Four" implant system are superior to conventional cantilever prostheses to reduce stress on the bone and the superstructure around implants. 2. The rest implant was of the greatest advantage to stress distribution on bone, implant and superstructure. 3. With same number of implants, distally tilted implants are preferred to conventional cantilever prostheses for reducing the length of cantilever.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.3
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• pp.3-12
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• 2015

Recently, various studies have been attempted to provide a biological information monitoring service through integrating with the web service. The medical information transmission standard ISO/IEEE 11073 PHD defines the optimized exchange protocol ISO/IEEE 11073-20601 based on the No-IP to exchange the biometric information between the ISO/IEEE 11073 agent and the manager. It's system structure based on the No-IP using ISO/IEEE 11073-20601 is not suitable for providing a remote biological information monitoring services. That is because it is difficult to provide to control and manage the biological information measurement devices, which have installed IP protocol stack at the remote. Furthermore, ACSE and CMDISE in ISO/IEEE 11073-20601 are not suitable to provide U-healthcare services based on IoT because they are complicated and difficult to implement it caused by the structural complexity. In order to solve the problems, in this paper, we propose the biological information monitoring architecture based on ISO/IEEE 11073 DIM/REST of IoT environment to provide the biological information monitoring service based on IoT. To do this, we designed biological information monitoring system architecture based on IoT and the message exchange protocol of ISO/IEEE 11073 DIM/REST between the ISO/IEEE 11073 agent and the ISO/IEEE 11073 manager. In order to verify the realistic possibility of the proposed system architecture, we developed the service prototype.

• The Korean Journal of Nuclear Medicine
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• v.26 no.2
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• pp.274-279
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• 1992

Clinical role of $^{99m}Tc-MIBI$ myocardial scintigraphy in the diagnosis of coronary artery disease (CAD) is now well accepted, however, the role of it in the identification of viable myocardium in patients with chronic CAD has not yet been clarified. To determine the usefulness of rest-injected $^{99m}Tc-MIBI$ scan as a marker of myocardial viability, the regional uptake of this agent at rest was compared with that of $^{201}Tl$ on reinjection and 24 hours after reinjection images. Subject patients were 13 chronic CAD patients who showed irreversible perfusion defect(s) on standard pharmacologic (dipyridamole) stress-redistribution images. Immediately after the redistribution images were obtained, 37 MBq thallium was injected at rest, and images were reacquired at 10 minutes and 24 hours after reinjection. After then 740 MBq $^{99m}Tc-MIBI$ was injected, and 1 hour later rest MIBI myocardial imaging was performed. Five sets of imagestress, redistribution, reinjection, delayed images of thallium, and rest image of MIBI) were then analyzed qualitatively and quantitatively. Left ventricle was arbitrarily divided into 9 segments (apex, basal and apical portions of anterior, septal, inferior, and lateral walls). Seven patients and 30 regions showed a fixed perfusion defect on the stress-redistribution images. Among 30 regions, 15 showed positive uptakes and 6 showed negative uptakes on both $^{201}Tl$ reinjection/delayed images and $^{99m}Tc-MIBI$ rest images. Five regions showed only thallium uptake and were regarded as viable clinically. Of four regions which showed only $^{99m}Tc-MIBI$ uptake, two were regarded as viable, while the other two were regarded as a nonviable scar tissue clinically. In conclusion, $^{201}Tl$ reinjection technique was more reliable in the identification of viable myocardium. However, the role of $^{99m}Tc-MIBI$ in identification of viable myocardium was still remained to be clarified because 2 of 9 regions showed only $^{99m}Tc-MIBI$ uptake and were regarded as viable tissues.

• The Korean Journal of Nuclear Medicine
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• v.30 no.4
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• pp.502-506
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• 1996

Tc-99m myocardial perfusion agents such as Tc-99m sestamibi or Tc-99m tetrofosmin has advantages over T1-201 for myocardial perfusion scan fuck as low attenuation and easy availability. However, Tc-99m agents do not redistribute so they need to be given T times, namely after stress and at rest. To evaluate whether rest image is needed in patients showing normal stress image, 43 patients who underwent both myocardial perfusion scan and coronary angiography and showed normal stress images were evaluated. Findings of rest images of them were evaluated whether they change the diagnosis or treatment plans. Among 43 patients who showed normal stress myocardial perfusion imaging, 31 (72.1%) showed no additional informations. However, among 5 patients with vasospastic angina 4 (80%) showed abnormal rest images in spite of normal stress images. So, when vasospastic angina is suspected clinically, rest image could be helpful in identifying patients with coronary vasospasm. In conclusion, rest myocardial perfusion images were not helpful in 72.1 % of patients with angina when stress images were normal. In only exception was those with vasospastic angina.

• Korean Journal of Childcare and Education
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• v.9 no.5
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• pp.335-355
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• 2013

The purpose of this study was to investigate children's recognition and needs about rest and naps at child care education centers, in the view of respecting children's rights. The participants were 40 children(20 4 year olds and 20 5 year olds), attending B Public Child Care Education Center in Seoul. The research methods were accomplished by participant observation in project activities and interviews with semi-structured questions. The collections of this process which were recorded document materials and video materials were analyzed by transcribed method. The results of this study were as follows: First, the meaning of the children's recognized rest showed time for family together, time for fun play, time required when they were very stressful and angry, and time for eating delicious meals. Second, children recognized that nap time in the child care center was time for a forced nap, time for listening to quiet music, and time for feeling good after a nap. Third, as for the needs to take a rest and a nap for children, they wanted to rest when they came together at full day class after their friends had returned home, they wanted a special area except the classroom, and they wanted to be cared for by familiar adults. Based on these results of the study, future research directions were proposed in terms of respecting children's rights of enjoying a rest and a nap.

• The Korean Journal of Physiology
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• v.30 no.1
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• pp.43-51
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• 1996

This study was aimed to elucidate the changes in heart rate variability during treadmill exercise at various speeds and grades by spectral analysis. Thirty-three untrained male college students aged $20{\sim}26\;yr $were employed to exercise on a treadmill using 4 speeds (4.02, 5.47, 6.76 and 8.05 km/h) and 6 grades (0, 4, 8, 12, 16 and 20%). A fixed speed was selected for each session with the grade increased every 3 min. The electrocardiogram, respiration and the stepping activity were continuously recorded through an A/D converter system on the computer disk. Power spectra of heart rate variability (RRV) were obtained by use of a fast Fourier transform algorithm. The frequency domain was divided into 3 bands: $VLF\;(0{\sim}0.04\;Hz),\;LF\;(0.04 {\sim}0.15\;Hz)\;and\;HF\;(0.15{\sim}1.00\;Hz).$ Heart rate was $74.4{\pm}2.1\;beats/min$ at rest and showed a steady increase during treadmill exercise with increasing speed and grade up to $196.7{\pm}5.0\;beats/min.$ Total power of HRV was $35.0{\pm}6.7\;(beats/min)^{2}$ at rest and progressively decreased during exercise down to $1.9{\pm}0.3\;(beats/min)^{2}.$ The %VLF power of HRV was $34.5{\pm}3.7\; %$ at rest and showed no significant change during exercise except for a decrease observed at the highest intensity of exercise. The %LF power was $44.1{\pm}3.0\;%$ at rest and showed a progressive decrease down to $4.5{\pm}1.0\;%$ during those stages of exercise where heart rate was over 135 beats/min. The %HF power was $21.4{\pm}2.9\;%$ at rest and showed a progressive increase up to $87.1{\pm}6.7\;%$ during higher intensity exercise where heart rate was over 165 beats/min. Peak frequency of HF band was $0.200{\pm}0.018\;Hz$ at rest and was shifted to higher frequencies up to $0.909{\pm}0.048\;Hz$ at heart rates greater than 135 beats/min. Respiratory frequency was $18.0{\pm}1.5$ breaths/min at rest and significantly increased during exercise up to $53.0{\pm}3.7$ breaths/min. Stride frequency during treadmill exercise showed an increasing tendency with increasing speed from $55.6{\pm}0.9$ steps/min at 4.02 km/h to $81.2{\pm}0.6$ at 8.05 km/h. It was concluded that total power of HRV decreased progressively with increasing exercise intensity due to the withdrawal of parasympathetic activity. At higher exercise intensity, % LF power decreased and %HF power increased with its peak frequency shifted to higher values in a progressive mode with increasing speed and grade, reflecting a readjustment in the cardiovascular system and the increased respiration and its rate, respectively.

• The Journal of the Convergence on Culture Technology
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• v.9 no.6
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• pp.319-327
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• 2023

This study analyzes the risks of explosions of small LPG storage tanks installed at highway rest areas. For this purpose, the ranges of the effect of thermal radiation and overpressure caused by the BLEVE(Boiling Liquid Expansion Vapor Explosion)and VCE(Vapor Cloud Explosion) of a 2900-kg small LPG storage tank installed at highway rest areas were quantitatively evaluated by applying the Areal Location of Hazardous Atmospheres program. The ranges of influence of the derived explosion overpressure and thermal radiation were found to have a maximum radii of 336 m and 423 m, respectively. The study determined that those within 269 m could be severely injured by an explosion overpressure of 3.5 psi, and fatalities from thermal radiation of 10 kw/m² could occur within 192 m of the exploded storage tank. The safety management plan for the LPG storage tank was discussed while considering the auxiliary facilities of highway rest areas and the extent of the damage impact. These research results will help improve safety accident prevention regulations considering the environment and facilities of the rest areas as well as the safety management of small LPG storage tanks installed at highway rest areas.

• Journal of agricultural medicine and community health
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• v.33 no.2
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• pp.221-231
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• 2008

Abstract - Objective: This study was conducted to investigate the effect of work conditions on job stress of social workers in Seoul. Method: For this survey, a self-reported questionnaire was administrated to 1,000 social workers working in all of organization for social welfare practice in Seoul. The number of responded questionnaires was 431. Multiple linear regression analysis was used for job stress as the dependent variables and control variables. Results: The result of multiple linear regression analysis indicated that regular rest breaks had significantly effect on job stress level but long working hours did not. When regular rest breaks was guaranteed job stress of social workers significantly lowered 8.4 point. In addition standardized regression coefficients and partial R2 of regular rest breaks was the highest score among the variables. Conclusion: This study suggests that it is the most important to guarantee regular rest breaks in the work schedule in order to alleviate job stress of social workers.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.5
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• pp.443-453
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• 2012

This study examines visual perception and spatial satisfaction according to lighting conditions. Field measurements and surveys were performed in three rest space of university buildings where various lighting conditions were employed. Results indicate that overall impression of space improved when low color temperature, such as 3,000 K governed overall lighting environment and accent lighting was used for wall surfaces. Lighting conditions that kept uniform illuminance levels using area light sources containing fluorescent lamps with 6,500 K failed to keep favorable spatial satisfaction for space. High color temperature was not recommended for lighting in rest space. Asymmetrical illuminance levels formed by low color temperature such as 3000 K is recommended to keep positive mood and improve spatial satisfaction in rest space. Overall impression of the space was influenced by visual comfort, color temperature, spatial satisfaction and brightness. Spatial satisfaction for space was effectively impacted by psychological comfort, color temperature and overall impression for lighting conditions. Psychological comfort in space was influenced by color temperature, spatial satisfaction and visual annoyance from reflected light.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.1
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• pp.43.2-43.2
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• 2015

The massive limit of black holes (BHs) is observed as present day ten billion solar masses. We search for observational signatures of BHs that become extremely massive (EMBHs, 1-10 billion solar masses). I will report on the evolution of active galactic nuclei (AGNs) through the growth of BH mass and their dust emission strength. First, we measured 26 EMBH masses of quasars at 1