• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.1
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• pp.61-69
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• 2015

The objective of this study is to experimentally investigate the mixed flow behaviors and oxygen transfer characteristics of a vertical orifice ejector. The experimental apparatus consisted of an electric motor-pump, an orifice ejector, a circulation water tank, an air compressor, a high speed camera unit and control or measurement accessories. The mass ratio was calculated using the measured primary flow rate and suction air flow rate with experimental parameters. The visualization images of vertically injected mixed jet issuing from the orifice ejector were qualitatively analyzed. The volumetric oxygen transfer coefficient was calculated using the measured dissolved oxygen concentration. At a constant primary flow rate, the mass ratio and oxygen transfer coefficient increase with the air pressure of compressor. At a constant air pressure of the compressor, the mass ratio decreases and the oxygen transfer coefficient increases as the primary flow rate increases. The residence time and dispersion of fine air bubbles and the penetration of mixed flow were found to be important parameters for the oxygen transfer rate owing to the contact area and time of two phases.

• Journal of Korean Society of Steel Construction
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• v.24 no.1
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• pp.47-58
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• 2012

Dynamic behaviors of a corrugated steel plate tunnel lining system are examined under wind loads due to passing vehicles. Applied wind loads are simulated by applying the time functions as a vehicle moves through the tunnel. Wind loads are described by the pressure and suction as a vehicle arrives and leaves target positions in the tunnel. The tunnel lining is modeled using the simplified shell elements that retain the characteristics of the corrugated shapes. The displacements of the tunnel lining are evaluated under various conditions regarding wind velocity and the passing vehicles. The responses are found to increase as the vehicle velocity and wind velocity increase. A maximum displacement of 25mm occurs when two vehicles are crossing at the speed of 120km/h. A row of vehicles running consecutively minimally affects the dynamic responses with less than 2.5% of the dynamic responses enlarged and attributed to one running vehicle. It should be noted that the dynamic responses of the tunnel lining should be considered when there is no shotcrete applied.

• Journal of Korean Clinical Nursing Research
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• v.14 no.3
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• pp.73-85
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• 2008

Purpose: To examine effects of application of bronchodilators after endotracheal suction on peak air way pressure (PAP), lung compliance (Cdyn), oxygen saturation ($SpO_2$), heart rate (HR), blood pressure (BP), and respiration rate (RR) in cardiac surgery patients. Method: Data were collected from October 2007 to March 2008. Participants were patients who were treated with bronchodilators through mechanical ventilators in the SICU. At each suctioning, bronchodilators were applied immediately, and at 5, 10, and 15 minutes after suctioning. Besides PAP, Cdyn, $SpO_2$, HR, BP, RR, data on the frequency of side effects were also collected at 15, 30, 60 minutes after nebulization. Data were analyzed using the SAS program. Results: For application of bronchodilator right after suctioning and after, 5, 10 and 15 minutes, PAP and Cdyn did not show any significant differences although PAP was persistently decreased for 15 to 30 minutes and Cdyn increased at 15 minutes and decreased gradually after nebulization. Besides $SpO_2$, HR, BP, and RR, frequency of side effects did not show any significant difference. Conclusion: Bronchodilators can be applied at any time. However, the positive effects of bronchodilation right after suctioning on PAP and Cdyn, as also shown in previous reports, indicate it is a more efficient clinical process to maintain an adequate airway.

• Ocean and Polar Research
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• v.31 no.1
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• pp.11-29
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• 2009

Variability of sea surface temperature (SST) in the Japan/East Sea (JES) was studied using complex empirical orthogonal function (CEOF) analysis. Two daily data sets were analyzed: (1) New Generation 0.05o-gridded SST from Tohoku University, Japan (July 2002-July 2006), and (2) 0.25o-gridded SST from the Japan Meteorological Agency (October 1993-November 2006). Linkages with wind stress curl were revealed using 6-h 1o-gridded surface zonal and meridional winds from ancillary data of the Sea- WiFS Project, a special National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) product (1998-2005). SST anomalies (SSTA) were obtained by removing the seasonal signal, estimated as the leading mode of the CEOF decomposition of the original SST. Leading CEOF modes of residual SSTA obtained from both data sets were consistent with each other and were characterized by annual, semiannual, and quasi-biennial time scales estimated with 95% statistical significance. The Semiannual Mode lagged 2 months behind the increased occurrence of the anticyclonic (AC) wind stress curl over the JES. Links to dynamic processes were investigated by numerical simulations using an oceanic model. The suggested dynamic forcings of SSTA are the inflow of subtropical water into the JES through the Korea Strait, divergence in the surface layer induced by Ekman suction, meridional shifts of the Subarctic Front in the western JES, AC eddy formation, and wind-driven strengthening/weakening of large-scale currents. Events of west-east SSTA movement were identified in July-September. The SSTA moved from the northeastern JES towards the continental coast along the path of the westward branch of the Tsushima Current at a speed consistent with the advective scale.

• Journal of Korean society of Dental Hygiene
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• v.7 no.3
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• pp.213-230
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• 2007

The purpose of this study was to examine the state of infection control provided to members of Korean Dental Hygienists Association. The subjects in this study were dental hygienists who attended a symposium on July 1. 2006. after a survey was conducted, the answer sheets from 489 participants were analyzed, and the findings of the study were as follows: 1. Possession of disinfection room was being(72.7%), and person of infection control was zero(52.9%). Number of sterilizer was one(62.2%). 2. As a repetition choice, type of sterilizer was autoclave(97.9%), UV sterilizer(67.4%) and EO gas sterilizer(21.4%). As a repetition choice, infection materials was ethanol(84.1%). 3. Water tube of unit and chair was using of sterilized water(42.9%). Sterilizing of compressed air was no(69.0%). 4. Re-using of disposal was not using(62.5%), re-using disposal was suction tip(28.2%)(repetition choice) 5. In sterilization of instruments, hand-piece was every using time(28.4%), and reamer-file, bur, mirror, pincette, explorer, hand scaler and ultrasonic scaler were high in every using time. 6. Individual protection was high of using, cleaning of hands before treatment was every treatment(87.0%). Type of soap was liquid type in dental clinic(48.2%), infection soap in dental hospital(41.2%) and solid soap in public health center(50.6%). Answered that they need regular oral health education, and 82.9% respondents answered that they need oral health technicians in school. And 87.8% respondents needed individual oral health education for the benefit of better oral health.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.2
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• pp.271-278
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• 2021

This paper is a study on the implementation of smart filter system that recognizes the external environment and automatically removes pollutants according to pollution level. Recently, the occurrence of various pollutants in indoor and outdoor space has adversely affected the human body. Especially, various fine dust generated in the atmosphere becomes worse in closed residential space or office space. Although air pollution can be temporary lowered through ventilation, it is difficult to respond to fine dust changes in real time, and such problems become serious in the space where many people reside, such as at home or industry. Therefore, it is necessary to measure the pollution level of fine dust inside the residential space in real time and to reduce the pollution of indoor ventilation through automatic ventilation with the outside. To improve these problems, this paper proposes the implementation of smart filter system for external environment recognition. The structure of smart filter system that automatically measures air quality inside and outside, removes pollutants, implements the function, and confirms the operability by manufacturing prototypes. Finally, the effectiveness of the smart filter system for solving fine dust problems was examined.

• The Journal of Engineering Geology
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• v.33 no.1
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• pp.85-103
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• 2023

The in-situ remediation of a solidified stratum containing a large amount of fine-texture material like clay or organic matter in contaminated soil faces limitations such as increased remediation cost resulting from decreased purification efficiency. Even if the soil conditions are good, remediation generally requires a long time to complete because of non-uniform soil properties and low permeability. This study assessed the remediation effect and evaluated the field applicability of a methodology that combines pneumatic fracturing, vacuum extraction, and plasma blasting (the PPV method) to improve the limitations facing existing underground remediation methods. For comparison, underground remediation was performed over 80 days using the experimental PPV method and chemical oxidation (the control method). The control group showed no decrease in the degree of contamination due to the poor delivery of the soil remediation agent, whereas the PPV method clearly reduced the degree of contamination during the remediation period. Remediation effect, as assessed by the reduction of the highest TPH (Total Petroleum Hydrocarbons) concentration by distance from the injection well, was uncleared in the control group, whereas the PPV method showed a remediation effect of 62.6% within a 1 m radius of the injection well radius, 90.1% within 1.1~2.0 m, and 92.1% within 2.1~3.0 m. When evaluating the remediation efficiency by considering the average rate of TPH concentration reduction by distance from the injection well, the control group was not clear; in contrast, the PPV method showed 53.6% remediation effect within 1 m of the injection well, 82.4% within 1.1~2.0 m, and 68.7% within 2.1~3.0 m. Both ways of considering purification efficiency (based on changes in TPH maximum and average contamination concentration) found the PPV method to increase the remediation effect by 149.0~184.8% compared with the control group; its average increase in remediation effect was ~167%. The time taken to reduce contamination by 80% of the initial concentration was evaluated by deriving a correlation equation through analysis of the TPH concentration: the PPV method could reduce the purification time by 184.4% compared with chemical oxidation. However, the present evaluation of a single site cannot be equally applied to all strata, so additional research is necessary to explore more clearly the proposed method's effect.

• The Korean Nurse
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• v.32 no.1
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• pp.61-76
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• 1993

This study was done in order La provide basic data to a Fee System for hospital based Home Health Care services in Korea in the future. It was done by investigating activities provided to possible Home Health Care clients who could be discharged early from genera] hospitals and then estimating the nursing care fee according to each nursing activity based upon the time used for activity. The subjects of the study were selected by convenience sampling and consisted of 35 clients who might be clients for Home Nursing Care and were presently admitted to a medical- surgical ward of Y University Medical Center located in Seoul, Korea. The data collection period was from September 1, 1991 to September 30, 1991. The research in strum nets utilized for the study were a client selection criterial for Home Health Care developed by Choo(l991) and a check-list of nursing activity developed by researcher. The results of the study were as follows : 1. There were 44 different nursing activities provided in the seven days but the time was calculated for only 25 of the nursing activities. 2. Fees for the 25 different nursing activities were calculated by multipling the median of the average wage of a staff nurse having five years experience in an A grade general hospital to the Lime of the nursing activity. The results were compared with the insurance fee which the government recognized as an appropriate fee for that activity. The nursing activities with a lower calculated fee than the insurance fee were suction, catheterization, exercise education and dressing change. The nursing activities with a higher calculated fee than the government recognized fee were 1M injection and vital sign check. 3. There was a range of 1-15 nursing activities provided daily to the client. For the average number of nursing activities per day of 6.26 events the nursing care fee was calaulated at W 6136 per day. 4. Based upon the results of the study, a recommentdation for a Home Health Care fee per visit based on the nursing activities provided could be formulated for a Home Health Care fee system. It could be formulated as following: 1) Home health Care fee per visit $=[(direct{\;} nursing{\;}fee(direct{\;}nursing{\;}care{\;}time{\;}per{\;}activity{\;}{\times}{\;}average{\;}nursing{\;}wage)+indirect fee]{\times}average$ nursing activity per visit]+management fee+ materials fee+a travel fee In this way a nursing fee could be calculated based upon the result of the study of the nursing fees per visit. 2) Nursing activity fees per visit. = $([direct nursing{\;}care{\;}fee+indirect{\;}nursing{\;}fee]{\times}average$ number of nursing activities provided per visit] (W 6, 136) + travel fee(\ 5, 542) +management fee material $fee({\alpha})\{\;}16, 436+{\alpha}$ The nursing fee per visit as calculated in this research of $\{\;}15, 0000+{\alpha}$ could be adjusted according to the patient's condition or the use of high technology nursing care or according to the amount of time spent for travel. The nursing care fee per visit presented in this study can be validated through a Home Health Care demonstration project.

• Journal of Biomedical Engineering Research
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• v.30 no.1
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• pp.18-22
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• 2009

Laser has been widely used in various fields of medicine. Recently, noninvasive low-level laser therapeutic medical devices have been introduced in market. However, low-level laser cannot deliver enough photon density to expect positive therapeutic results in deep tissue layer due to the light scattering property in tissue. In order to overcome the limitation, this study was aimed to develop a negative pressure applied low-level laser probe to optimize laser transmission pattern and therefore, to improve photon density in soft tissue. In order to evaluate the possibility of clinical application of the developed laser probe, ex-vivo experiments were performed with porcine skin samples and laser transmissions were quantitatively measured as a function of tissue compression. The laser probe has an air suction hole to apply negative pressure to skin, a transparent plastic body to observe variations of tissue, and a small metallic optical fiber guide to support the optical fiber when negative pressure was applied. By applying negative pressure to the laser probe, the porcine skin under the metallic optical fiber guide is compressed down and, at the same time, low-level laser is emitted into the skin. Finally, the diffusion images of laser in the sample were acquired by a CCD camera and analyzed. Compared to the peak intensity without the compression, the peak intensity of laser increased about $2{\sim}2.5$ times and FWHM decreased about $1.67{\sim}2.85$ times. In addition, the laser peak intensity was positively and linearly increased as a function of compression. In conclusion, we verified that the developed low-level laser probe can control the photon density in tissue by applying compression, and therefore, its potential for clinical applications.

• Journal of Korean Neurosurgical Society
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• v.41 no.2
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• pp.100-104
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• 2007

Objective : Despite the widespread use of preoperative ventriculostomy in aneurysmal subarachnoid hemorrhage [SAH], there is no general consensus regarding the risk of bleeding associated with its use before aneurysm repair. This study was conducted to define the efficacy and rebleeding risk of ventriculostomy in aneurysmal SAH. Methods : The authors reviewed 339 consecutive patients with aneurysmal SAH who were treated at our hospital between January 1998 and December 2004. Results : Preoperative ventriculostomy was performed on 73 patients for acute hydrocephalus after aneurysmal SAH. The Hunt-Hess[H-H] grades of patients who underwent ventriculostomy were higher. Out of the 73 patients who underwent preoperative ventriculostomy, 58 [79%] demonstrated immediate clinical improvement after ventriculostomy. Of those same 73 patients 22 [30%] suffered aneurysmal rebleeding, whereas only 11 [4%] of the 266 patients who did not undergo ventriculostomy showed preoperative aneurysm rebleeding. The causes of rebleeding in the 22 patients who underwent ventriculostomy before surgery were related to the ventriculostomy procedure itself, subsequent cerebrospinal fluid [CSF] drainage, angiography and patient care procedures, such as endotracheal suction and nursing care. The mean time interval between SAH and surgery in the patients who underwent ventriculostomy was not statistically different from those who did not receive preoperative ventriculostomies [44.66 compared with 42.13 hours; p=0.73]. Conclusion : The preoperative ventriculostomy improved patients' clinical condition but increased the risk of rebleeding after aneurysmal SAH. When necessary, however, rapid change in transmural pressure during ventriculostomy must be avoided, careful management during ventricular drainage is needed, and surgery should be performed as soon as possible to prevent or reduce the incidence of rebleeding.