• Geomechanics and Engineering
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• 제32권3호
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• pp.255-270
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• 2023

One of the main parameters that affect the design of suction caisson-supported offshore structures is uplift behavior. Pull-out of suction caissons is profoundly utilized as the offshore wind turbine foundations accompany by a tensile resistance that is a function of a complex interaction between the caisson dimensions, geometry, wall roughness, soil type, load history, pull-out rate, and many other parameters. In this paper, a parametric study using a 3-D finite element model (FEM) of a single offshore suction caisson (SOSC) surrounded by saturated soil is performed to examine the effect of some key factors on the tensile resistance of the suction bucket foundation. Among the aforementioned parameters, caisson geometry and uplift loading as well as the difference between the tensile resistance and suction pressure on the behavior of the soil-foundation system including tensile capacity are investigated. For this purpose, a full model including 3-D suction caisson, soil, and soil-structure interaction (SSI) is developed in Abaqus based on the u-p formulation accounting for soil displacement (u) and pore pressure, P.The dynamic responses of foundations are compared and validated with the known results from the literature. The paper has focused on the effect of geometry change of 3-D SOSC to present the soil-structure interaction and the tensile capacity. Different 3-D caisson models such as triangular, pentagonal, hexagonal, and octagonal are employed. It is observed that regardless of the caisson geometry, by increasing the uplift loading rate, the tensile resistance increases. More specifically, it is found that the resistance to pull-out of the cylinder is higher than the other geometries and this geometry is the optimum one for designing caissons.

• Archives of Plastic Surgery
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• 제45권5호
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• pp.449-457
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• 2018

Background Although previous studies have focused on determining prognostic and causative variables associated with fistula-related complications after head and neck reconstructive surgery, only a few studies have addressed preventive measures. Noting that pooled saliva complicates wound healing and precipitates fistula-related complications, we devised a continuous suction system to remove saliva during early postoperative recovery. Methods A continuous suction system was implemented in 20 patients after head and neck reconstructive surgery between January 2012 and October 2017. This group was compared to a control group of 16 patients at the same institution. The system was placed orally when the lesion was on the anterior side of the retromolar trigone area, and when glossectomy or resection of the mouth floor was performed. When the orohypopharynx and/or larynx were eradicated, the irrigation system was placed in the pharyngeal area. Results The mean follow-up period was $9.2{\pm}2.4$ months. The Hemovac system was applied for an average of 7.5 days. On average, 6.5 days were needed for the net drain output to fall below 10 mL. Complications were analyzed according to their causes and rates. A fistula occurred in two cases in the suction group. Compared to the control group, a significant difference was noted in the surgical site infection rate (P<0.031). Conclusions Clinical observations showed reduced saliva pooling and a reduction in the infection rate. This resulted in improved wound healing through the application of a continuous suction system.

• 한국해안해양공학회:학술대회논문집
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• 한국해안해양공학회 2006년도 추계학술대회 발표논문집 Proceedings of Coastal and Ocean Engineering in Korea
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• pp.89-92
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• 2006

• 한국기계가공학회지
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• 제17권1호
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• pp.82-88
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• 2018

An experimental study was performed on the orifice nozzle system that generates micro-bubbles by air self-suction using a venturi nozzle. This study experimentally investigates the amount of air sucked into the venturi nozzle and the number of micro-bubbles generated by the orifice nozzle system in Cases 1 and 2. The experimental conditions were varied by changing the diameter of the orifice nozzle (d=2~7 mm) and the number of holes of the perforated plate nozzle (n = 2-12). In Case 1, the air self-suction was more than 2 LPM at $d{\leq}4mm$. When d = 4 mm, the total number of bubbles was 29,777, and it was confirmed that micro-bubbles occupied approximately 65% of the total number of bubbles. In Case 2, the air self-suction was maintained constant at approximately 2.5 LPM regardless of the number (n) of holes. The total amount of bubbles increased when n increased but remained constant at approximately 44,000 when $n{\geq}7EA$. It was also confirmed that more than 80% of all bubbles were micro-bubbles when $n{\geq}10EA$. Thus, the number of micro-bubbles increased by approximately 15% compared to the experimental result of Case 1, which was optimized with d = 4 mm.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제11권1호
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• pp.57-70
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• 2007

The effects of variable viscosity, blowing or suction on mixed convection flow of a viscous incompressible fluid past a semi-infinite horizontal flat plate aligned parallel to a uniform free stream in the presence of the wall temperature distribution inversely proportional to the square root of the distance from the leading edge have been investigated. The equations governing the flow are transformed into a system of coupled non-linear ordinary differential equations by using similarity variables. The similarity equations have been solved numerically. The effect of the viscosity temperature parameter, the buoyancy parameter and the blowing or suction parameter on the velocity and temperature profiles as well as on the skin-friction coefficient and the Nusselt number are discussed.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 추계학술대회 초록집
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• pp.165.2-165.2
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• 2011

Flow with suction to water turbine must be in stable state at small hydraulic power plant. But because of water level fluctuation and water gate effect according to irregular supply of cooling water, it would happen to produce bubble and vortex and finally lead to problems in power-plant system. With utilizing the concept design of double size gate, surface water overflowed the overhead of gate for stable flow at suction. We developed the overflow condition and analyzed the design factor with existed one such as water level(overflow amount) and overhead of water gate(overflow figure). Flow test and CFD simulation say that flow have stable state around suction and 20% of wave reduction effect at surface layer after surface water overflow.

• Tuberculosis and Respiratory Diseases
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• 제65권3호
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• pp.198-206
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• 2008

연구배경: 폐쇄관을 이용한 기관내 흡인은 임상적으로 중한 환자에게 생리적인 이점이 있지만, 병원성 균주에 의한 기관지 내의 집락화가 증가될 수 있다는 보고가 있다. 비용증가는 폐쇄흡인의 또 다른 제한점이다. 본 연구는 폐쇄흡 인 및 개방흡인에 따른 병원균주의 집락화와 인공환기관련폐렴의 빈도와 가격효율성을 비교해보고자 시행되었다. 방 법: 각각 한 달의 간격을 사이에 두고 내과계 중환자실에 입원한 환자들을 대상으로 다중사용 개방흡인, 단일사용 개방흡인, 다중사용 폐쇄흡인을 순차적으로 시행하였다. 비용, MRSA의 기관지내 집락화, 인공환기폐렴의 발생 률을 분석하였다. 결 과: 106명의 환자가 연구 대상으로 포함이 되었고, 이 중 20명의 환자가 다중사용 개방흡인을, 42명이 단일사용 개방흡인을, 44명이 다중사용 폐쇄흡인술을 시행받았다. MRSA의 집락화와 인공환기관련폐렴의 빈도는 세 군간에 의미있는 차이를 보이지 않았다. 입원 일당 소모되는 비용은 다중사용 개방흡인이 $10.58, 단일사용 개방흡인이 $28.27, 다중사용 폐쇄흡인의 경우 $23.76인 것으로 나타났다. 결 론: 다중사용 폐쇄흡인을 매 48시간마다 교환하는 경우 MRSA 집락화와 인공환기폐렴 발생 빈도는 비슷하였고, 기관내 흡인술에 있어서 비용면에서도 효율적인 방법임을 알 수 있었다.

• 한국정보통신학회논문지
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• 제16권3호
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• pp.635-642
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• 2012

본 논문에서는 치과용 통합공급장치를 실시간으로 제어 및 모니터링할 수 있고 그 결과를 Wi-Fi 무선랜 통신을 통해 송수신이 가능한 제어시스템을 개발하였다. 개발한 제어시스템은 안드로이드 운영체제를 내장하기 위해 S3C6410 ARM 칩을 이용하여 설계하였다. 개발한 제어시스템은 Wi-Fi 통신, RS485, 리녹스 2.6 및 안드로이드 운영체제 2.0을 내장하도록 보드를 개발하였다. 개발한 제어시스템은 치과용 통합공급장치에 내장되어 있는 정수기, 컴프레서, 석션을 실시간으로 제어하였다. 실험결과, 개발한 제어시스템은 각 제어기 모듈과 연계하여 정수기, 석션 및 컴프레서를 실시간으로 제어하였고, 그 상태 값을 RS485 통신을 이용하여 제어시스템에 실시간으로 표시하였다.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2002년도 추계학술대회 논문집
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• pp.251-255
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• 2002

Eutrophic matters accumulated on the bottom of sea, river and lake cause red tide phenomenon in ocean and outbreak green algae in river and lake. Systems are developed to remove the noxious deposit. But the existing systems remove not only the eutrophic matters but also natural materials, sand, pebbles etc. that should remain at the bottom. This paper describes a new system that can safely, and economically take away the noxious deposit in underwater. High pressure water jet is used to induce vortices in the triangular suction section, and air-lifting pump to lift up the deposit. The mixture of the water and deposit is filtered through the drum filters. An under camera shows the under water situation along the moving direction of the system that is controlled by a remote operator. This remote controlled moving system obliterate the necessity of the diver that usually costs high. The experimental results show the effectiveness of the suggested system.

• 한국간호교육학회지
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• 제23권3호
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• pp.330-340
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• 2017

Purpose: This study was conducted to explore the relationship between simulation-based clinical judgment and performance ability for tracheal suction in nursing students. Methods: With a convenience sampling, 207 nursing students participated in this descriptive study. Lasater clinical judgment rubric was used for self-reported clinical judgment in addition to observe the skill of tracheal suction using a checklist. Data were analyzed by descriptive statistics, t-test and Pearson's correlation coefficients using the SPSS/WIN 22. Results: A scenario with pneumonia patient was developed to observe the skill of tracheal suction during simulation-based practices. Then self-reported clinical judgment was scored. The mean score of total sum of clinical judgment, total mean of clinical judgment, and performance skill were $36.44{\pm}4.82$, $13.44{\pm}1.71$, and $42.32{\pm}5.05$, respectively. Statistically, students having good skills in suction showed significant differences in clinical judgment of interpreting (p=.031) compared to students having fair skills. Conclusion: The results of this study show that a structured debriefing method utilizing Lasater clinical judgment rubric is helpful. Also, simulation-based practice related to adult nursing in the respiratory system was useful for increasing the core basic skills among nursing students.