• 중환자간호학회지
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• 제17권2호
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• pp.42-54
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• 2024

Purpose : This study aimed to assess the effectiveness of an advanced practice nurse (APN)-driven ventilator weaning protocol for patients undergoing cardiac surgeries. Methods : A retrospective analysis was conducted on 226 patients admitted to the intensive care unit (ICU) of a tertiary hospital between January and June 2020, following a cardiac surgery. Patients were divided into an APN protocol-applied group (experimental group, n=152) and a control group managed based on doctors' judgment (n=74). Ventilator weaning criteria and clinical outcomes, including duration of ventilation, length of ICU stay, and rate of reintubation, were compared between the two groups. Results : Patients in the control group were older and had a higher incidence of massive bleeding from chest tube drainage (>100 cc/hr) at baseline. The average duration of ventilation was significantly shorter in the experimental group compared to the control group (7.44 vs. 21.61 hours, p <.001). Furthermore, the mean length of ICU stay was shorter in the experimental group compared to the control group (47.96 vs. 77.97 hours, p <.001). There was no difference in the rate of reintubation between the two groups. Conclusion : These findings suggest that an APN-driven ventilator weaning protocol can improve clinical outcomes without significant complications. These results support the adoption of APN-driven mechanical ventilator weaning protocols in clinical practice.

• The Korean journal of internal medicine
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• 제39권1호
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• pp.160-171
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• 2024

Background/Aims: The effectiveness of remdesivir treatment in reducing mortality and the requirement for mechanical ventilation (MV) remains uncertain, as randomized controlled trials (RCTs) have produced conflicting results. Methods: We searched MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and other data resources to find RCTs published prior to April 10, 2023. The selection of studies, assessment of risk of bias, and meta-analysis were conducted according to PRISMA guidelines. The primary outcomes were all-cause mortality and the need to initiate MV. Results: A total of 5,068 articles were screened, from eight RCTs comprising 11,945 patients. The meta-analysis found that, compared to standard care or placebo, remdesivir treatment provided no significant all-cause mortality benefit (pooled risk ratio [RR], 0.93; 95% confidence interval [CI], 0.85-1.02; 8 studies; high certainty evidence), while subgroup analyses revealed a trend towards reduced mortality among patients requiring oxygen but not MV (pooled RR, 0.88; 95% CI, 0.77-1.00; 6 studies; I² = 4%). The need to initiate MV (pooled RR, 0.74; 95% CI, 0.59-0.94; 7 studies; moderate certainty evidence) in remdesivir-treated patients was also reduced compared to controls. Remdesivir significantly increased clinical improvement and discharge and significantly reduced serious adverse events. Conclusions: In this systematic review and meta-analysis of RCTs, it was found that remdesivir treatment did not show a substantial decrease in the risk of mortality. However, it was linked to a reduction in the necessity for additional ventilator support, suggesting remdesivir could be beneficial for COVID-19 patients, particularly those who are not on MV.

• 설비공학논문집
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• 제14권12호
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• pp.1102-1139
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• 2002

A review on the papers published in the Korean Journal of Air-Conditioning and Refrigerating Engineering in 2000 and 2001 has been done. Focus has been put on current status of research in the aspect of heating, cooling, ventilation, sanitation and building environment. The conclusions are as follows. (1) Most of fundamental studies on fluid flow were related with heat transportation of facilities. Drop formation and rivulet flow on solid surfaces were interesting topics related with condensation augmentation. Research on micro environment considering flow, heat, humidity was also interesting for comfortable living environment. It can be extended considering biological aspects. Development of fans and blowers of high performance and low noise were continuing topics. Well developed CFD technologies were widely applied for developing facilities and their systems. (2) Most of papers related with heat transfer analysis and heat exchanger shows dealt with convection, evaporation, and channel flow for the design application of heat exchanger. The numerical heat transfer simulation studies have been peformed and reported to show heat transfer characteristics. Experimental as well as numerical studies on heat exchanger were reported, while not many papers are available for the system analysis including heat exchanger. (3) A review of the recent studies on heat pump system shows that performance analysis and control of heat pump have been peformed by various simulations and experiments. The research papers on multi-type heat pump system increased significantly. The studies on heat pipe have been examined experimently for change of working characteristics and strut lure. Research on the phase change has been carried out steadily and operation strategies of encapsulated ice storage tank are reported experimentally in several papers. (4) A review of recent studies on refrigeration/air conditioning system have focused on the system performance and efficiency for new alternative refrigerants. Evaporation and condensation heat transfer characteristics are investigated for tube shapes and new alternative refrigerants. Studies on components of refrigeration/air conditioning system are carried to examine efficiency for various compressors and performance of new expansion devices. In addition to thermophysical properties of refrigerant mixtures, studies on new refrigerants are also carried out, however research works on two-phase flow seemed to be insufficient. (5) A review of the recent studies on absorption cooling system indicates that heat and mass transfer phenomena have been investigated to improve absorber performance. Various experimental data have been presented and several simulation models have been proposed. A review of the recent studies on duct and ventilation shows that ventilation indices have been proposed to quantify the ventilation performance in buildings and tunnels. Main efforts have been focused on the applications of ventilation effectiveness in practice, either numerically using computational fluid dynamics or experimentally using tracer gas techniques. (6) Based on a review of recent studies on indoor thermal environment and building service systems, research issues have mainly focused on many innovative ideas such as underfloor air-conditioning system, personal environmental modules, radiant floor cooling and etc. Also, the new approaches for minimizing energy consumption as well as improving indoor environmental conditions through predictive control of HVAC systems, various activities of building energy management and cost-benefit analysis for economic evaluation were highlighted.

• Tuberculosis and Respiratory Diseases
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• 제46권4호
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• pp.564-573
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• 1999

배 경: 폐색전증의 임상증상은 비특이적이어서 임상증상 만으로 진단이 어렵다. 폐색전증의 진단을 위하여 폐환기관류주사가 선별검사로 널리 사용되고 있으나 PIOPED(the prospective investigation of pulmonary embolism diagnosis) 연구의 결과처럼 저 중등도 확률 소견일 경우 폐색전증의 진단을 내리거나 배제하는데 도움이 되지 않으며 PIOPED 연구의 약 60%의 환자가 저 중등도 확률 소견을 보인다. 이러한 환자들은 확진을 위해 폐동맥조영술이 필요하지만 침습적이며 쉽게 시행할 수 없다는 단점이 있다. 최근 가공 영상을 줄이고 조영제 일시주사 기술로 혈관구조를 조영할 수 있게 한 spiral CT가 폐동맥조영술을 대신하여 폐색전증의 진단에 이용하는 전향적 연구가 이루어지고 있다. 이에 저자들은 폐색전증의 진단에서 spiral CT의 유용성을 알아보고자 폐색전증을 의심하여 spiral CT를 찍은 환자를 대상으로 후향적 조사를 시행하였다. 방 법: 1994년 10월부터 1997년 2월까지 삼성서울병원에 입원한 환자 중 폐색전증이 의심되어 spiral CT를 시행한 20명(남자 : 13명, 여자 : 7명, 평균연령 : 58세)을 대상으로 하였다. 폐색전증의 위험인자로 심부정맥혈전증과 고령이 가장 많았고 폐색전증이 의심된 임상증상으로 갑자기 발생하였거나 악화된 호흡곤란이 가장 많았다. 결 과: 20명의 환자 중 spiral CT로 폐색전증으로 진단된 환자는 16명이었고 3명은 각각 폐암, 폐기종 환자에서 발생한 폐농양을 동반한 폐렴, 울혈성 심부전에 의한 흉막삼출증으로 색전을 확인할 수 없었다. 나머지 1명은 spiral CT에서 정상 소견이었다. 폐환기관류주사에서 고확률로 판정된 12명의 환자중 1명에서 spiral CT로 폐기종 환자에서 발생한 폐농양을 동반한 폐렴인 위양성으로 진단할 수 있었다. 폐환기관류주사에서 저 중동도 확률을 보이는 4명 중 3명에서 spiral CT로 폐색전증을 진단할 수 있었다. 야간, 기계호흡 등의 이유로 폐환기관류주사를 시행치 못한 3명에서 spiral CT로 폐색전증을 진단 또는 배제할수 있었다. 폐색전증으로 진단된 16명 중에서 폐엽동맥 수준 이상의 색전은 11례 였으며 분절하동맥 수준 이하의 색전 경우는 5례였다. 결 론: 이상의 결과로 spiral CT는 폐분절동맥까지의 폐색전증의 진단에 유용하며, 특히 중심성 폐색전증의 확진과 배제에 있어서 중요한 진단방법이라고 생각된다. 향후 폐색전증의 진단에 spiral CT가 진단과정에 도입될 수 있는지에 대한 대규모의 전향적인 연구가 필요할 것으로 사료된다.

• 환경영향평가
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• 제30권4호
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• pp.187-202
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• 2021

본 연구는 경상남도 창원시의 열환경 개선을 위해 열환경, 찬공기의 생성·유동성 및 지리적 특성을 분석하여, 지역 맞춤형 바람길 조성 방안을 검토하였다. 공간분석(spatial analysis), 원격탐사(remote sensing) 기법을 활용하여 창원시의 지표면온도, 토지피복 및 토지이용, 바람장, 경사도를 측정하고 이를 통해 바람길 분석모형을 구성하였다. 2020년도를 기준으로 분석한 결과, 창원시는 전반적으로 찬공기 생성에 유리한 토지피복 특성을 가지고 있으나, 대부분의 도심지 지역의 기온이 가장 높게 나타났다. 북창원 생활권, 진북면, 웅동, 웅천동 등 지역의 기온이 비교적 높으며, 산지지역에서 평균 풍속이 높고, 시가지에서 평균 풍속이 낮은 전형적인 경향을 보였다. 이에 따라 북창원 생활권, 구 창원 도심지, 호계리·평성리 지역, 창포만 지역을 열환경 개선지역으로 도출하고 각 지역의 특성을 고려한 지역 내 찬공기 유입 및 주변 산지, 저수지, 공원 지역 등과의 바람 유동성 확보를 통해 기온저감 및 대기질을 개선할 수 있는 다양한 방안들을 제안하였다.

• 복식
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• 제52권8호
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• pp.29-39
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• 2002

It was increased leisure hours by automation and computerization of industry. Many people spend on hours in enjoying leisure sports, and then. nowadays, Many women tend to prefer casual wear to formal suits. The purpose of this research was to design of outdoor-wear that improve the functional and aesthetic effects for clothing comfort. Total 4 design prototype consisting of jumper and slacks were developed for this research. Outdoor-wear design forced on armhole type of jumper and ease of the back crotch length of slacks to improve the functional and aesthetic effects. And Outdoor-wear design focused on color harmony to aesthetic effects. Ease amount and materials of jumper and slacks were controlled. Design A: Jumper was designed as dropped shoulder with set-in steeve and band collar, A break-away zipper to facilitate ventilation control were made the area of back of jumper and the area of outside seam line of slacks Color of jumper and slacks were olive green color. Ease amount of the crotch length of slacks pattern was constructed as 7% of total crotch length: Design B 4DM cut pattern were applied to the jumper and slacks pattern. A break-away zipper to facilitate ventilation control were made the area of back of jumper and the area of inside seam line of thigh. Color of jumper and slacks were grey and orange color. Ease amount of the crotch length of slacks pattern was constructed as 5% of total crotch length. Design C : Jumper was designed as the set in sleeve and hood. and A break- away zipper to facilitate ventilation control were made the ares of the armhole and elbow. Color of jumper and slacks were ivory and orange color. Ease amount of the crotch length of slacks pattern was constructed as 5% of total crotch length. Design D : Jumper was designed as raglan sleeve. Color of jumper and slacks were olive green color. Ease amount of the crotch length of slacks pattern was constructed as 5% of total crotch length. Total six females, ages 20-45, served as subjects for this research. Subjects have standard body type, generally, wearing 66 size of ready-to-wear clothing. The performance of the newly designed outdoor-wear was evaluated for their effectiveness in several aspects such as conditions of skin temperature, sensory evaluation of comfort during body movements, appearance and color harmony and aesthetic collar design. Design 3 was appeared to be the most positive in aesthetic evaluation and functional effects of design 2 of 4DM cut pattern was appeared to be beter than other designs.

• 한국철도학회논문집
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• 제10권5호
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• pp.511-519
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• 2007

대구지하철 방화사건 이후 방재시설이 많이 개선되었지만 아직 인명안전에 대한 확실한 대안을 제시하지 못한 상태이다. 본 논문은 전동차 화재 시 인명안전의 보장을 입증하는 방안에 대하여 정량적으로 평가한 논문으로 화재 열차가 터널 내에 정차할 경우를 가정하여 시나리오를 구성하고, 최악의 시나리오에 대한 가상 화재 및 피난시뮬레이션 기법을 활용하여 대피안전성을 평가하였다. 평가결과 현행 지하철 터널구조하에서의 인명안전을 확보하기 위해 승강장(스크린 도어 설치)에서는 터널상부에서 승강장 천정부를 연결하는 제연환기구(덕트 포함)를 설치할 경우, ASET시간을 연장할 수 있기 때문에 대피안전성 확보가 가능하다. 또한 터널중앙 환기구에서는 배기통과 완전히 분리된 별도의 특별 피난계단을 연결하여 설치하여야만 터널 중앙환기구를 통하여 대피하는 승객의 대피안전성의 확보가 가능한 것으로 입증 제시한바, 실물화재실험의 수행없이 가상화재시뮬레이션에 의하여 대피안전성을 정량적으로 입증하였다.

• 한국안전학회지
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• 제27권2호
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• pp.65-71
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• 2012

Changes in the styles of communities are leading of increases in the number of high-rise apartments and commercial-apartment structures. Tall high-rise structures, while presenting unique economies of scale and cost effectiveness, tend to be highly engineered and complex structures. In the event of a fire, this complexity in design also results in a complexity in the behavior of fire propagation and control. High-rise structures are among the most potentially dangerous due to the high population density in the building, and the inherent limitations on evacuation and on fire control services. One of the most critical points of fire propagation is the movement of fire through the outer wall structures. Controlling such propagation is essential in controlling the spread of the fire throughout the building itself, as well as controlling the potential for its spread to adjacent buildings. In this study, we will be examining the potential for fire control design and effects mitigation using a 1/4.5 scale model. The primary focus of the study will be the effects of extended balconies into the structure of high-rise apartments. The authors will also consider the effectiveness of reduced-scale model tests.

• 한국산학기술학회논문지
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• 제21권11호
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• pp.892-897
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• 2020

본 연구에서는 간접식 증발냉각 장치의 냉각 성능을 예측하고 다양한 공기 유량 및 물 분무 유량 조건을 만족하는 성능 상관식을 제안한다. 기존의 플라스틱 열교환기는 공조 공간의 크기에 따라 금형을 새로 제작해야 하기 때문에 높은 효율에도 불구하고 잘 사용하지 않았다. 한편 단프라시트는 일반적으로 두께가 얇아 열교환이 우수하고, 특히 제작이 매우 용이하다. 따라서 열교환기를 단프라시트로 제작할 경우 금형이 별도로 필요하지 않아 열교환기 제작 비용을 크게 절감할 수 있다. 이에 본 연구에서는 단프라시트로 다채널 열교환기를 제작하여 간접식 증발냉각 장치를 제작하였다. 성능 실험장치는 열교환기, 물 분사 노즐, 터보홴, 항온조, 순환 펌프, 온도 센서, 습도 센서, 차압식 유량계 및 자료획득 장치로 구성하였다. 증발냉각 시 공기 유량이 증가하면 유용도가 감소하였고, 수공비에 따라 유용도 최적점이 존재하였다. 등온 조건에서 냉각 성능을 예측하는 상관식과 실내 환기 온도와 외기 상태를 반영하는 성능 상관식을 제안하였다. 상관식들의 냉각 성능 오차는 4 % 이내였다.

• 한국항공우주학회지
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• 제30권8호
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• pp.21-29
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• 2002

본 연구는 다공벽과 공동을 사용한 피동제어법을 천음속 습공기 유동에서 발생하는 충격파와 경계층 간섭에 적응하였다. 지배방정식은 액적성장 방정식과 완전히 결합된 2차원, 비정상, 압축성 Navier-Stokes 방정식이며, 3차 오더 MUSCL 타입의 TVD 기법을 사용하였다. 또 난류모델로는 Baldwin-Lomax 모델을 적용하였다. 본 연구에서 적용한 제어법의 유용성을 조사하기 위해 유동의 전압손실과 충격파 변위의 시간의존성 거동을 해석하였다. 수치계산 결과로부터 본 연구의 피동제어기법을 통해 천음속 습공기 유동에서 발생하는 충격파/경계층 간섭으로 인한 전압손실이 상당히 감소하였고, 익에서 충격파 운동을 억제하는 것으로 나타났다. 또 다공영역의 위치가 본 연구의 제어법의 효과에 상당한 영향을 준다는 것이 발견하였다.