• Journal of Chest Surgery
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• 제25권4호
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• pp.391-397
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• 1992

Postoperative hypoxemia in the absence of hypoventilation occurs more often after thoracic or upper abdominal surgery than lower abdominal operations or surgery on extremities. Although the factors which produce postoperative alveolar collapse have not been fully evaluated, the dominant factor of postoperative hypoxia is shunt of blood passing collapsed alveoli and the postoperative pain is associated with restriction of depth of breathing, sighing and movement. In 1979, the first successful clinical usage of epidurally administered morphine was done by Behar and associates for control of postoperative pain. This study was carried out for twenty patients who received posterolateral thoracostomy with Bled resection between May 1990 and May 1991 and who were primary spontaneous recurrent pneumothoraxes. We selected ten of twenty patients, one after the other and treated with epidural analgesia as study group and the remainder ten were grouped as control. Epidural catheters were inserted for study group before operation through T12-L1, 2 interspinous process at the pain clinic or operation room by anesthesiogist and then the drugs[0.25% Bupivacaine 15ml mixing with morphine 3mg] were instillated through the catheter before extubarion and once a day until 4th day, and the patients of control group were treated intermittently by Demerol 50mg intramuscularly for postoperative pain control. The epidural catheters were removed at postoperative 4th day. Observations were done about vital aigns, a-BGA, tidal volume, FVC and occurence of adverse effects during postoperative 2hr, 8hr, 1st day, 2nd day, 7th day in both groups. The results were as follows; [1] Tidal volume[85.1$\pm$29.8%R VS 60.8$\pm$20.5%R, p<0.05] and FVC[53.7$\pm$14.2%R, VS 35.5$\pm$9.l%R, p<0.01] were significantly improved in study group compared with control group during the first day of operation. [2] But the improvement of FVC was delayed after stopping of epidural analgesia[postoperative 7th day, 97.5$\pm$12.3%R VS 83.9$\pm$15.6%R, P <0.05]. [3] Others were statistically not significant. [4] The side effects of epidural analgesia were identified such as urinary retention[2 cases], itching sensation[1 case] and headache[1 case], but there was no need for active treatments.

• Membrane and Water Treatment
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• 제8권4호
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• pp.355-367
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• 2017

In India, the current operation of condenser cooling system & effluent disposal system in existing power plants aims to reduce drawal of seawater and to achieve Zero Liquid Discharge to meet the demands of statutory requirements, water scarcity and ecological system. Particularly in the Steam-Electric power plants, condenser cooling system adopts Once through cooling (OTC) system which requires more drawal of seawater and effluent disposal system adopts sea outfall system which discharges hot water into sea. This paper presents an overview of closed-loop technology for condenser cooling system and to achieve Zero Liquid Discharge plant in Steam-Electric power plants making it lesser drawal of seawater and complete elimination of hot water discharges into sea. The closed-loop technology for condenser cooling system reduces the drawal of seawater by 92% and Zero Liquid Discharge plant eliminates the hot water discharges into sea by 100%. Further, the proposed modification generates revenue out of selling potable water and ZLD free flowing solids at INR 81,97,20,000 per annum (considering INR 60/Cu.m, 330 days/year and 90% availability) and INR 23,760 per annum (considering INR 100/Ton, 330 days/year and 90% availability) respectively. This proposed modification costs INR 870,00,00,000 with payback period of less than 11 years. The conventional technology can be replaced with this proposed technique in the existing and upcoming power plants.

• 청정기술
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• 제16권1호
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• pp.39-45
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• 2010

본 연구에서는 국내 우리텍사의 PVDF계 중공사 막을 4 bundle 씩 묶어 모듈을 제작하였으며, 처리용량은 10 ton/day로 설정하여 반응조 내 부유고형물(suspended solid; SS) 의 농도구배가 없도록 하부로부터 간헐 폭기하는 방식을 선택하여 부산 수영하수처리장에 pilot plant를 설치하였다. Pilot plant는 정상 운전을 위하여 하수처리장의 폭기조로부터 유입된 mixed liquor suspended solid (MLSS) 1,000 ppm 정도의 원수를 시험 여과하고, 세척수로 2회 세척, 10% 에탄올 용액으로 1회 세척, 그리고 NaOCl 5% 용액으로 1회 세척 과정을 거치고 마지막으로 세척수로 최종 세척한 후 운전하였다. 결과적으로, 화학세정 후 membrane bioreactor (MBR) 내의 잔류수를 원수로 운전한 결과 SS 제거효율이 99.9% 이상을 보이고 있는 결과와 폭기조 유입수를 원수로 운전하여, 여과 수량은 초기 조건에 비해 16% 감소, suction pressure 는 30% 상승하고 있음을 확인한 결과를 연속 운전 조건으로 설정하였다. 연속 운전한 결과, 유입수 mixed liquor suspended solid (MLSS)가 1,900 mg/L의 조건에서 SS 제거 효율은 99.99% 이었으며 여과수량은 $42{\sim}52L/m^2$ h, suction pressure가 16~20 cmHg로 안정 상태로 운전되고 있음을 확인하였다. 다만, 여과수 저장조의 유출구와 유입구에서의 SS 제거 효율에 영향을 미치는 조류의 발생 억제에 관한 방법이 재고되어 여과수의 재이용 범위를 설정할 필요가 있을 것으로 판단된다.

• 대한기계학회논문집A
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• 제24권4호
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• pp.848-857
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• 2000

A pick-and-place operation in 3-dimensional environment is basic operation for human and multi-purpose manipulators. However, there may be a difficult problem for such manipulators. Especially, if the object cannot be moved with a single grasp, regrasping, which can be a time-consuming process, should be carried out. Regrasping, given initial and final pose of the target object, is a construction of sequential transition of object poses that are compatible with two poses in the point of grasp configuration. This paper presents a novel approach for solving regrasp problem. The approach consists of a preprocessing and a planning stage. Preprocessing, which is done only once for a given robot, generates a look-up table which has information of kinematically feasible task space of end-effector through all the workspace. Then, using the table planning automatically determines possible intermediate location, pose and regrasp sequence leading from the pick-up to put-down grasp. Experiments show that the presented is complete in the total workspace. The regrasp planner was combined with existing path.

• 공학교육연구
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• 제15권4호
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• pp.109-117
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• 2012

The purpose of this study is to give the preliminary data and suggestion for introducing and spreading e-learning engineering education through analyzing learning behaviors, learning motivations, and satisfaction of e-learning engineering students. Especially, this comparative study analyzes each research domain according to majors and grades, thereby suggesting more specific and practical results. 2,745 students registered in 38 subjects of e-learning in 2 Universities were analyzed for this study. The study result shows that engineering students are attending around 2 e-learning subjects with a duration of about 30 minutes once a week. The main of learning motivation for e-learning was not easy test level and feasibility of acquiring credit but advantages of e-learning such as freedom of time and space, learning by repetition. The satisfaction scores of e-learning were lower compared to the aspects of system and contents Based on these results, first, an active spread of e-learning to engineering education is necessary because the demand from the engineering students is high enough and they have desirable learning behavior and learning motivation for it. Second, the characteristics of grades need to be taken into consideration on operation of e-learning. Third, a successful e-learning process needs more meticulous and active operation.

• Computers and Concrete
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• 제29권4호
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• pp.209-217
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• 2022

In order to analyze the static and dynamic structural characteristics of the Obermeyer gate under overflow conditions, the force characteristics and vibration characteristics of the shield plate structure are studied based on the fluid-solid coupling theory. In this paper, the effects of the flow rate, airbag pressure and overflow water level on the structural performance of shield plate of air shield dam are explored through the method of controlling variables. The results show that the maximum equivalent stress and total deformation of the shield plate decrease first and then increase with the flow velocity. In addition, they are positively correlated with the airbag pressure. What's more, we find that the maximum equivalent stress of the shield plate decreases first and then increases with the overflow water level, and the total deformation of the shield plate decreases with the overflow water level. What's more importantly, the natural frequency of the shield structure of the Obermeyer gate is concentrated at 50 Hz and 100 Hz, so there is still the possibility of resonance. Once the resonance occurs, the free edge of the shield vibrates back and forth. This work may provide a theoretical reference for the safe and stable operation of the shield of the Obermeyer gate.

• 수산해양기술연구
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• 제59권2호
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• pp.172-180
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• 2023

Although it is highly dependent on the production of coastal and offshore fishing, the Fishing Vessels Safety Fisheries Act was enacted in 2019 due to the continuous increase in marine accidents of coastal and offshore fishing vessels. However, the law is too focused on fishing and navigation in certain waters and does not contain accident-preventive content. Ministry of Oceans and Fisheries proposes a plan to revise the Fishing Boat Safety Fishing Act through legal comparison with Japan's Seafarers' Labor Sanitation Rules. It also proposes an amendment that includes the content of the Seafarers Act on post-accident action obligations. Under the Fishing Vessels Safety Fishing Act, the safety fishing education is implemented for specific people and adopts a method of delivery education after completing the education. The reason for this is that the educational requirements are not sufficient compared to the number of education personnel. Moreover, four hours of education are conducted once a year, which is not suitable for insufficient educational conditions. For efficient safety fishing education, improvement measures are proposed compared to education in the United States and the United Kingdom.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.203-203
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• 2000

The P&S(Power Plant Simulation System) is a powerful simulation software system for the dynamic behavior of power plants. The P&S module libraries provide plant models with higher flexibility of dynamic simulations for process and control designs. The P&S software was effectively available for PCS based on Linux and modem workstations based on Unix. The P&S was applied for simulating the dynamic behaviors of the SOVR(Supercritical Once-Through Variable Pressure Reheater) according to the operations such as stan-up, shutdown, load following, load change and trip in order to obtain an optimal operation procedure for Unit 5/6 of Taeahn fossil power plant consisted of SOVRs and steam turbines.

• Journal of Electrical Engineering and Technology
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• 제13권1호
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• pp.97-104
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• 2018

This paper proposes supplementary control of conventional coordinated control of a power plant which directly affects network frequency. The supplementary control with dynamic matrix control is applied for 1000 MW power plant with ultra-supercritical (USC) once-through boiler. The supplementary control signal is added to the boiler feedforward signal in the existing coordinated control logic. Therefore, it is a very practical structure that can maintain the existing multi-loop control system. This supplementary controller uses the step response model for the power plant system, and on-line optimization is performed at every sampling step. The simulation results demonstrate the effectiveness of the proposed supplementary control in a wide operating range of a practical 1000 MW USC power plant simulator. These results can contribute the stable operation of power system frequency.

• 대한의사협회지
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• 제61권11호
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• pp.638-642
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• 2018

Surgery is a very hands-on area of medical care, in that surgeons identify problems in patients' bodies and directly change them through operations. Therefore, it is not only necessary for surgeons to have a high level of expertise, but also to take considerable responsibility for the outcomes of each operation. However, surgery, which was once an object of envy, has long been a process to avoid, due to various circumstances, such as abnormal medical expenses in the medical field and social phenomena that avoids difficult work. It is unfortunate that medical professionals do not receive sympathy from others within the same medical field because of the general difficulties of the profession. The fundamental problem in this situation is the abnormal profit structure of the Korean medical system. Efforts by various related organizations will be needed to objectively evaluate the problems of the current medical insurance system and to make reasonable adjustments considering the difficulty, frequency, and resource-intensiveness of medical care.