http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
복강경수술시 Trendelenburg 체위와 Reverse Trendelenburg 체위는 최고흡기압과 동맥혈 가스의 변화에 영향을 주는가 ?
심규대,남상범,정장환,이종석 대한정맥마취학회 2001 정맥마취 Vol.5 No.3
Background: Laparoscopic surgery has increased in popularity due to its small skin incision, reduced postoperative pain and short hospital day. But increased abdominal pressure caused by CO_2 insufflation and Trendelenburg position or reverse Trendelenburg position affects cardiovascular function and pulmonary ventilation. Some studies suggested that Trendelenburg position affect more serious results on pulmonary ventilation than reverse Trendelenburg position, but others do not. So we designed this study to compare the difference of peak inspiratory pressures and arterial blood gases between Trendelenburg position and reverse Trendelenburg position in laparoscopic surgery. Methods: Twenty patients undergoing laparoscopic operation were randomized into two groups. Group Ⅰ (n = 10) was laparoscopic gynecological surgery under Trendelenburg position, and group Ⅱ (n = 10) was laparoscopic cholecystectomy under reverse Trendelenburg position. All patients were mechanically ventilated (a tidal volume of 12 ㎖/㎏ at a respiratory rate of 12 breaths/minute) with 50% nitrous oxide and 50% oxygen with enflurane. We measured peak inspiratory pressure, PaO_2 and PaCO_2 at pre-CO_2 insufflation, 10 minute after CO_2 insufflation, 30 minute after CO_2 insufflation and 10 minute after CO_2 deflation, respectively. Results: There were no significant differences between the two groups in peak inspiratory pressure, PaCO_2 and PaO_2. Conclusions: We suggest that there are no changes in pulmonary ventilation between Trendelenburg and reverse Trendelenburg position in patients undergoing laparoscopic surgery.
장래 해수수질 변화에 따른 머신러닝 기반 해수담수 전력비 예측 모형 개발
심규대,고영희 한국수자원학회 2021 한국수자원학회논문집 Vol.54 No.12S
The electricity cost of a desalination facility was also predicted and reviewed, which allowed the proposed model to be incorporated into the future design of such facilities. Input data from 2003 to 2014 of the Korea Hydrographic and Oceanographic Agency (KHOA) were used, and the structure of the model was determined using the trial and error method to analyze as well as hyperparameters such as salinity and seawater temperature. The future seawater quality was estimated by optimizing the prediction model based on machine learning. Results indicated that the seawater temperature would be similar to the existing pattern, and salinity showed a gradual decrease in the maximum value from the past measurement data. Therefore, it was reviewed that the electricity cost for seawater desalination decreased by approximately 0.80% and a process configuration was determined to be necessary. This study aimed at establishing a machine-learning-based prediction model to predict future water quality changes, reviewed the impact on the scale of seawater desalination facilities, and suggested alternatives. 본 연구는 머신러닝 기반의 분석으로 해수담수화(Desalination) 시설의 전력비 예측모델의 가능성을 검토하였다. 해수담수화 주요 공정인 역삼투(Seawater Reverse Osmosis) 시설의 전력비 예측 모델을 개발하고, 전력비 산정에 영향을 미치는 인자를 분석하였으며, 해수 수질 중에서 선정된 수온 및 염분도 측정자료를 활용하여 검토하였다. 국립해양조사원(Korea Hydrographic and Oceanographic Agency, KHOA)의 2003년부터 2014년까지의 자료를 이용하였으며, 모형의 구조는 시행오차법(Trial & Error)으로 하이퍼파라미터를 최적화하여 머신러닝 기반의 예측 모델을 구축하고, 장래 해수 수질을 예측하였다. 해수 수온은 기존 패턴과 유사할 것으로 예측되었고, 염분도는 과거 측정자료 범위 이내로 최대값이 점차 감소되는 경향을 보여 해수담수화의 전력비가 약 0.80% 감소하는 것으로 검토되었다. 본 연구는 머신러닝 기반의 예측 모델을 구축하여 장래 수질 변화 예측하였으며, 해수 수질 변동의 영향 및 대안을 제시했다는데 의의가 있다.
오리피스를 고려한 송수관로 수충격 완화방법에 대한 연구
심규대,강용석,정준연,Mohamed Abdellatif,김동균 한국방재학회 2018 한국방재학회논문집 Vol.18 No.7
본 연구에서는 쿠웨이트 Azzour WDC (Water Distribution Center) II 송수시설 운영 시 정전으로 인하여 발생할 수 있는 관로 내 압력을 검토하고 대비방안을 모색하였다. 이를 위하여 관로 내 흐름을 모의하는 상용소프트웨어 SURGE로 펌프가 급정지되는 경우의 초기조건을 적용하여 관로내 급변류를 모의하였다. 모의 결과, 정상상태 대비 최대 1.7배(Wafra)에서 4.2배(Mina Abdulla)의 수충압이 발생할 수 있음을 확인하였으며, 이에 대비하기 위한 시설로 Mina Abdullah 송수라인은 서지탱크(121.4 m3)와 오리피스(275 mm)를. Wafra 송수라인은 서지탱크(43.1 m3)와 오리피스(300 mm)를 설계 후 시공하였다. 시운전을 통하여 수충격 방지 시설의 성능은 검증되었고, 발생한 수충압은 예측한 허용 압력 이내로 확인되었다. This study investigated the variation of pressure for a pumping station in Azzour Water Distribution Complex, (WDC) II, and attempted to overcome the problem of pressure suppression in pipelines, due to power failure. The transient flow was calculated using the commercial program SURGE, and the resulting value was used in the initial conditions of a pump shutdown. The simulation results show that the maximum pressure was 1.7 times (for Wafra) and 4.2 times (for Mina Abdullah) higher than the normal pressure in the steady state. The surge protection facilities were accordingly designed and surge vessels were constructed with orifice dimensions of 121.4 m3×275 mm for Mina Abdullah and 43.1 m3×300 mm for Wafra, respectively. The performance of the surge protection facilities on commission, were verified and the surge pressure remained within the expected allowable pressures considering the occurrence of a water hammer.
심규대(Shim, Kyu Dae),김창용(Kim, Chang Ryong),정준연(Choung, Joon Yeon),김동균(Kim, Dong Kyun) 대한토목학회 2021 대한토목학회논문집 Vol.41 No.5
본 연구에서는 서해에 위치한 대산산업단지 해수담수화 시설에 필요한 전력비를 계산하고, 해수온도 및 염분도 변화에 따른 안전도를 고려한 전력비 기준을 산정하였다. 입력 자료(온도 및 염분도)는 국가해양환경정보통합시스템(MEIS, Marine Environment Information System) 22년 자료(1997~2018년)를 이용하고, 해수공정에서 사용되는 전력량은 RO막 제조사에서 제공되는 프로그램(Q-Plus v3.0)을 활용하였다. 금회연구에서는 해수담수화 시설물 설계시 합리적인 전력비 운영 가이드라인을 제시했다는데 의의가 있다. 해수담수화 역삼투압 공정은 약2.10~2.90 kWh/m³의 전력비가 소요되며, 에너지 안전도 95 % 기준으로 2.80 kWh/m³의 전력비가 해수담수화 시설을 운영할 때 고려되어야 하는 것으로 검토되었다. This study focused on safety aspects surrounding energy consumption in the seawater desalination process in the Daesan Industrial Complex located on the West Sea coast. The safety index for energy consumption was evaluated under different salinities and temperatures of the incoming seawater. Temperature and salinity input data for the 1997-2018 period were obtained from the Marine Environment Information System, and the power required for reverse osmosis (RO) was applied to the program as per the data provided by the RO membrane manufacturer (Q-Plus v3.0). Notably, reasonable energy consumption guidelines were proposed during the design of the desalination facilities; in this regard, the desalination process required approximately 2.10-2.90 kWh/㎥ electrical power. Moreover, the energy safety based on 95 % was estimated to be 2.80 kWh/㎥ when the desalination facility was operated.