• Nuclear Engineering and Technology
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• 제51권1호
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• pp.163-169
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• 2019

The robust controller synthesis and analysis of the water level process in the U-tube system generator (UTSG) is addressed in this paper. The parameter uncertainties of the steam generator (SG) are modeled as multiplicative perturbations which are normalized by designing suitable weighting functions. The relative errors of the nominal SG model with respect to the other operating power level models are employed to specify the weighting functions for normalizing the plant uncertainties. Then, a robust controller is designed based on ${\mu}$-synthesis and D-K iteration, and its stability robustness is verified over the whole range of power operations. A gain-scheduled controller with $H_{\infty}$-synthesis is also designed to compare its robustness with the proposed controller. The stability analysis is accomplished and compared with the previous QFT design. The ${\mu}$-analysis of the system shows that the proposed controller has a favorable stability robustness for the whole range of operating power conditions. The proposed controller response is simulated against the power level deviation in start-up and shutdown stages and compared with the other concerning controllers.

• 대한간호학회지
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• 제45권1호
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• pp.84-96
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• 2015

Purpose: This study was done to investigate the motivational, physical and affective benefits of exergaming in community dwelling older adult women. Methods: The research design was a nonequivalent control group pre-test and post-test design. Sixty-one older adult women over the age of 65 were recruited from 6 community senior centers to participate in the 8 week exercise intervention or control group. Six centers were divided into one of three groups: exergame, qigong exercise, or control. The exergame and the qigong exercise group received 16 sessions, scheduled twice a week, with each session lasting 50 minutes. Test measures were completed before and after the 8 week intervention period for all participants. Measures included: Grip strength, chair stand, 6 m walking, balance, geriatric depression scale, vitality and intrinsic motivation. Results: There were significant improvements in the exergame and qigong exercise group for grip strength, chair stand, 6m walking, balance, vitality and intrinsic motivation at the end the 8-week program compared with the control group. Conclusion: The exergame could be an effective alternative for older adult women to group exercise classes.

• 대한의생명과학회지
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• 제7권2호
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• pp.91-98
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• 2001

The present study was prospectively designed to assess the clinical effect of leukocyte-depleted blood cardioplegic solution (BCS) on myocardium during cardiac surgery with cardiopulmonary bypass (CPB). 30 adult patients scheduled for elective cardiac surgery were divided into control group (n＝15), which infused routine BCS, and leukocyte-depleted (LD) group (n＝15), which infused leukocyte-depleted BCS. Total and differential leukocyte counts in BCS, malondialdehyde (MDA) and troponin-T (TnT) concentrations in coronary sinus blood, and cardiac index (CI) were measured at preoperative and postoperative period. The BCS in LD group had less total leukocyte counts with neutropenia than that in control group (P＜0.01). MDA (3.70$\pm$0.35 vs 5.90$\pm$0.57 $\mu$mol/L, p<0.05) and TnT (0.42$\pm$0.03 vs 0.60$\pm$0.09 ng/mL, p<0.05) were significantly low in LD group compared with control group, while LD group had higher CI (3.28$\pm$0.16 L/min/$m^2$, p<0.05) than control group (2.69$\pm$0.18 L/min/$m^2$). These results suggest that leukocyte-depleted blood cardioplegic solution has a better myocardial protective effect with less generations of oxygen free radicals and ischemia/reperfusion injury.

• 한국추진공학회지
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• 제1권2호
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• pp.67-73
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• 1997

본 논문에서는 다목적 실용위성에 장착될 자세제어용 추력기의 개발 현황에 대하여 기술하였다. (주)한화는 해외기술이전 업체인 미국의 TRW사로 부터 1.0 lbf MRE-1 추력기의 설계/해석 및 제작에 대한 전반적인 기술이전을 받아 이를 토대로 국산화에 성공하여 납품하였다. 이 추력기들은 1999년 7월 발사 예정인 다목적 실용위성에 장착되어 운용될 것이다. 단일 하이드라진 추력기는 60년대 말 부터 위성체 자세제어용 추진기관으로 실용화된 기술로서 현재까지도 가장 신뢰도가 높고 경제적인 것으로 평가되고 있다. 본 논문에서는 이러한 단일 하이드라진 추력기의 규격, 성능해석 또는 모사 및 제작에 관한 기술적인 사항을 일부 소개하였다.

• 한국추진공학회지
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• 제20권1호
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• pp.28-36
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• 2016

본 논문에서는 핀틀을 이용한 가변추력 고체 추진기관의 추력을 제어하기 위하여 이론적으로 모델을 구하고 압력 제어기를 설계하였다. 고전적인 모델 선형화 및 비례-적분제어를 설계했을 때 실제 모델의 비선형성에 의해 발생하는 제어기 성능 저하를 줄이기 위해 이득 계획 기법을 적용하였다. 시스템의 특징을 고려하여 연소관 내부 체적 변화에 따라 이득을 조절하는 방법과, 연소관 내부 압력에 의해 이득을 조절하는 방법으로 두종류의 이득 계획 제어기를 설계하였다. 각 제어기를 가변 추력기 모델에 적용하여 폐루프 시스템 응답특성을 비교하였으며 가변 추력 추진기관 특성에 따라서 어떤 제어기를 선택하는 것이 유리한지 제안하였다.

• 대한전기학회논문지:전력기술부문A
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• 제55권9호
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• pp.351-358
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• 2006

In this paper, DSPOCS(Digital Switchgear-Panel Operation and Control Solution) is designed, which is the intelligent inference based operation and control solution to obtain the safety and reliability of electric power supply in substation based on IED. DSPOCS is designed as a scheduled monitoring and control task and a real-time alarm inference task, and is interlinked with BRES(Bus Reconfiguration Expert System) in the required case. The intelligent alarm inference task consists of the alarm knowledge generation part and the real-time pattern matching part. The alarm knowledge generation part generates automatically alarm knowledge from DB saves it in alarm knowledge base. On the other hand, the pattern matching part inferences the real-time event by comparing the real-time event information furnished from IEDs of substation with the patterns of the saved alarm knowledge base.; Especially, alarm knowledge base includes the knowledge patterns related with fault alarm, the overload alarm and the diagnosis alarm. In order to design the database independently in substation structure, busbar is represented as a connectivity node which makes the more generalized graph theory possible. Finally, DSPOCS is implemented in MS Visual $C^{++}$, MFC, the effectiveness and accuracy of the design is verified by simulation study to the typical distribution substation.

• 기본간호학회지
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• 제22권3호
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• pp.287-296
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• 2015

Purpose: The purpose of this study was to examine the effects of forced air warming on intraoperative and postoperative body temperature, postoperative shivering and pain in patients undergoing laparoscopic cholecystectomy. Methods: A quasi-experimental design with nonequivalent control group was utilized. Fifty eight patients scheduled for laparoscopic cholecystectomy were recruited and assigned to the experimental group (n=29) or control group (n=29). For the experimental group, forced air warming was applied from right after induction and up to one hour after surgery. Body temperature, shivering score and pain score were measured in both groups at 15 minute intervals. Data were collected from September, 2013 to April, 2014. Data were analyzed using t-test, Bonferroni test and repeated measures ANOVA. Results: The experimental group showed higher body temperature than the control group during surgery. After surgery the experimental group showed higher body temperature, lower shivering and less pain compared to the control group. Conclusion: Results show that forced air warming is effective in enhancing body temperature and reducing shivering and pain. Therefore, forced air warming is recommended as an operative nursing intervention.

• 임상간호연구
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• 제17권3호
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• pp.319-328
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• 2011

Purpose: This study was done to identify nursing interventions clinically applicable to relieve displeasure and anxiety of patients having an operation in which loud noise was unavoidable. Methods: Participants were 34 patients scheduled to have a total knee replacement. They were assigned to either the control (17 patients) or experimental (17 patients) group. Data were collected from September to November 2010. The instruments used for the survey included noise-control earplugs, a noise level meter (TES-1358) and a structured scale measuring degree of noise perception, displeasure and anxiety. Data were analyzed using frequency, percentage, standard deviation, $x^2$-test, and t-test with the SPSS WIN 18.0 program. Results: Hypothesis 1: 'The displeasure levels of the experimental group of patients wearing earplugs will be lower than the control group patients without earplugs' was accepted (t=-20.769, p<.001). Hypothesis 2: 'The anxiety levels of the experimental group of patients wearing earplugs will be lower than the control group patients without earplugs' was accepted (t=-6.298, p<.001). Conclusion: Based on these findings, the wearing of earplugs for patients having a surgical operation with loud noises is recommended as an effective nursing intervention to relieve patient displeasure and anxiety during their surgical operations.

• Journal of Animal Science and Technology
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• 제49권4호
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• pp.451-458
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• 2007

본 연구는 포유중인 모돈에서 이유 전과 후에 성선자극호르몬 투여 및 예정시각 인공수정이 번식성적에 미치는 영향을 조사하였다. 포유중인 모돈은 대조구, 이유 전 2일 및 이유 후 1일에 성선자극호르몬을 주사 하였다. 성선자극호르몬을 주사한 모돈의 1/2은 발정확인 후 24 및 36시간에 인공수정 하였고, 1/2은 GnRH 주사 후 24 및 36시간에 각각 예정시각 인공수정 하였다.포유중인 모돈에서 대조구, 이유 전 및 이유 후 성선자극호르몬을 투여 하여 발정재귀를 관찰한 결과 이유 후 성선자극호르몬 투여구가 발정재귀율이 높게 조사 되였으나 유의적 차이는 없는 것으로 조사되었다. 성선자극호르몬 투여가 발정재귀 시간에 미치는 영향을 조사한 결과 이유 전 성선자극호르몬 투여구가 발정 재귀시간이 유의적으로 짧은 것으로 조사되었다(P<0.01). 포유중인 모돈에서 성선자극호르몬을 이유 전 또는 이유 후에 투여한 후 인공수정을 실시한 결과 분만율과 산자수는 유의적인 차이는 없었다. 예정시각 인공수정에 따른 산자수는 이유 전 성선자극호르몬 처리구와 이유 후 성선자극호르몬 처리구에서 예정시각 인공수정 처리구가 발정관찰인공수정에 비하여 유의적으로 적었다(P<0.01).이상의 결과를 종합해 보면 성선자극호르몬은 포유중인 모돈에서 난포를 발육시킬 수 있으며, 이유 전 성선자극호르몬의 투여는 발정재귀일의 단축 효과를 기대 할 수 있으나 포유돈에 있어 발정재귀율 개선과 향상된 번식성적과의 상관 관계 정립을 위한 추가적인 연구가 필요할 것으로 사료된다.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1995년도 춘계공동학술대회논문집; 전남대학교; 28-29 Apr. 1995
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• pp.185-192
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• 1995

A common control model used to implement computer integrated manufacturing(CIM) is based on the hierarchical decomposition of the shop floor activities, in which supervisory controllers are responsible for all the interactions among subordinates. Although the hierarchical control philosophy provides for easy understanding of complex systems, an emerging manufacturing paradigm, agile manufacturing, requires a new control structure necessary to accommodate the rapid development of a shop floor controller. This is what is called CSCW(computer supported cooperative work)-based control or component-based heterarchical control. As computing resources and communication network on the shop floor become increasingly intelligent and powerful, the new control architecture is about to come true in a modern CIM system. In this paper, CSCW-based control is adopted and investigated, in which a controller for a unit of device performs 3 main functions - planning, scheduling and execution. In this paper, attention is paid to a planning function and all the detailed planning activities for CSCW-based shop floor control are identified. Interactions with other functions are also addressed. Generally speaking, planning determines tasks to be scheduled in the future. In other words, planning analyzes process plans and transforms process plans into detailed plans adequate for shop floor control. Planning is also responsible for updating the process plan and identifying/resolving replanning activities whether they come from scheduling or execution.