• 여성건강간호학회지
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• 제17권5호
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• pp.454-462
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• 2011

Purpose: This paper identified the effects of kangaroo care (KC) on maternal self-esteem and the growth and physiological stability of premature infants hospitalized in the neonatal intensive care unit. Methods: The experiment was conducted with an experimental group of 17 infants, and a control group of 17 infants selected by convenience sampling. KC was given to the infants one time a day for 30 minutes after feeding for two weeks. Their weight was measured every morning, and their physiological stability was measured in terms of their body temperature, respiratory rate, heart rate, oxygen saturation, and stability of the cardio-respiratory system in premature infants (SCRIP) score, as physiological responses at every 10 minutes during the intervention. Maternal self-esteem was assessed by a maternal self-report inventory. Results: The experimental group showed significant increase in the self-esteem of mothers. Also, KC was effective on physiological stabilization of preterm infants. Conclusion: This study suggests that KC can be provided in clinical settings more widely in Korea as one of the nursing interventions aimed at promoting maternal self-esteem as well as infants' physiological stabilization.

• 한국연소학회지
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• 제17권1호
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• pp.48-57
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• 2012

Laminar lifted propane coflow-jet flames diluted with nitrogen were experimentally investigated to determine heat-loss-related self-excitation regimes in the flame stability map and elucidate the individual flame characteristics. There exists a critical lift-off height over which flame-stabilizing effect becomes minor, thereby causing a normal heat-loss-induced self-excitation with O(0.01 Hz). Air-coflowing can suppress the normal heat-loss-induced self-excitation through increase of a Peclet number; meanwhile it can enhance the normal heat-lossinduced self-excitation through reducing fuel concentration gradient and thereby decreasing the reaction rate of trailing diffusion flame. Below the critical lift-off height. the effect of flame stabilization is superior, leading to a coflow-modulated heat-loss-induced self-excitation with O(0.001 Hz). Over the critical lift-off height, the effect of reducing fuel concentration gradient is pronounced, so that the normal heat-loss-induced self-excitation is restored. A newly found prompt self-excitation, observed prior to a heat-loss-induced flame blowout, is discussed. Heat-loss-related self-excitations, obtained laminar lifted propane coflow-jet flames diluted with nitrogen, were characterized by the functional dependency of Strouhal number on related parameters. The critical lift-off height was also reasonably characterized by Peclet number and fuel mole fraction.

• Transactions on Control, Automation and Systems Engineering
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• 제3권3호
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• pp.176-180
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• 2001

In this papers, we derive a simple kinematic and dynamic formulation of an unmanned electric bicycle. We also check the controllability of the stabilization problem of bicycle. We propose a new control algorithm for the self stabilization of unmanned bicycle with bounded wheel speed and steering angle by using nonlinear control based on the sliding patch and stuck phenomena which was introduced by W. Ham. We also propose a sort of optimal control strategy for steering angle and driving wheel speed that make the length of bicycle\`s path be the shortest. From the computer simulation results, we prove the validity of the proposed control algorithm.

• 전기학회논문지P
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• 제51권2호
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• pp.60-67
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• 2002

This paper presents a control approach for designing a self tuning fuzzy controller for a synchronous generator excitation and SVC system. A combination of thyristor-controlled reactors and fixed capacitors (TCR-FC) type SVC is recognized as having the most flexible control and high speed response, which has been widely utilized in power systems, is considered and designed to improve the response of a synchronous generator, as well as controlling the system voltage. The proposed parameter self tuning algorithm of fuzzy controller is based on the steepest decent method using two direction vectors which make error between inference values of fuzzy controller and output values of the specially selected PSS reduce steepestly. Using input-output data pair obtained from PSS, the parameters in antecedent part and in consequent part of fuzzy inference rules are learned and tuned automatically using the proposed steepest decent method. The related simulation results show that the proposed fuzzy controller is more powerful than the conventional ones.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 추계학술대회 논문집 학회본부
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• pp.48-50
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• 1994

In this paper, the optimal fuzzy controller of exciter and governor in synchronous generator improve the stability of power system with varying loads and disturbances in power system. Parameters of the proposed fuzzy controller were optimally self-tuned by the steepest descent method and were applied to power system stabilization. The related simulation results show that the proposed control technique are more powerful than the conventional ones for reductions of undershoot and for minimization of settling time.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2009년도 춘계 학술대회 제21권1호
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• pp.539-540
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• 2009

이 연구에서는 레올로지 제어를 이용하여 자기충전용 ECC(Engineered Cementitious Composite)를 개발하는데 그 목적을 두었으며, 레올로지 제어를 위하여 시멘트 페이스트에 대한 시멘트와 혼화제(감수제, 증점제)의 흡착정도를 평가하였고, 모르타르에 대하여 자기충전성과 유동특성을 평가하였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(5)
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• pp.315-318
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• 2002

In this paper, we have studied about the determination methode of the operating frequency, and the design technique for the self-exited electronic ballast. Because we use the saturation characteristics of the ferrite core, the variation of the B/H curve characteristics for the selected core in the most important factor for the stabilization. Although it is impossible to fix the operation frequency, the self-exited electronic ballast is widely used because of its cost and the simplicity of its structure.

• 조명전기설비학회논문지
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• 제23권2호
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• pp.175-181
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• 2009

본 논문에서는 전력계통의 안정도를 향상시키기 위하여 동기 발전기와 정지형 무효전력 보상기에 대한 파라미터 자기조정 퍼지제어기의 설계 기법을 제시한다. 제안된 퍼지제어기의 파라미터 자기조정 알고리즘은 퍼지제어기의 추론값과 전력계통안정화 장치의 출력값들 사이의 오차를 감소시키는 두 개의 방향 벡터를 사용하는 최급강하법에 기초를 둔다. 전력계통안정화 장치로부터 얻어진 입 출력 데이터쌍을 사용하여, 퍼지추론 규칙의 전건부와 후건부에서의 파라미터들은 제안된 최급강하법에 의해 자동조정되고 학습되어진다. 시뮬레이션 결과, 제안된 퍼지제어기가 종래의 제어기보다 우수한 제어성능을 보임을 확인하였다.

• 한국해안·해양공학회논문집
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• 제31권4호
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• pp.209-220
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• 2019

해빈 안정화를 위해 거치되는 강성 구조물의 규모는 해빈의 자기 치유 능력이 구현되는 해빈 대순환 과정이 훼손되지 않는 범위에서 결정되어야 하나 최근 지나치게 대형화 되어 광폭 잠제도 빈번하게 차용되고 있는 실정이다. 이러한 시각에 기초하면 Irie et al.(1994)가 제안한 왜도 된 연흔모양 매트는 규모가 크지 않다는 점에서 현재 선호되는 광폭잠제의 대안이 될 수 있을 것으로 판단된다. 전술한 왜도 된 연흔모양 매트의 해빈 안정화 효과는 매트의 유수 단면 축소부에서 강제되는 와류가 run-down 시 외해방향으로 이송되는 표사를 얼마나 효과적으로 포획할 수 있느냐에 따라 결정되는 것으로 추정된다. 본 논문에서는 이러한 가설을 확인하기 위해 수치모의를 수행하였다. 수치모형은 Navier-Stokes 식과 물리기반 지형모형으로 구성하였으며, 모의 결과 왜도 된 연흔모양 매트 정점부에서 강제된 와류에 의해 포획된 표사가 해안 방향으로 이송되는 등 왜도 된 연흔모양 매트의 해빈 안정화 효과를 구성하는 주요 기작과 해빈 안정화 효과를 확인할 수 있었다.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.91-92
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• 2006

The fine-tuned dendrons provide unique supramolecular self-assemblies in various environments such as in water, organic media, and solid-liquid interfaces. They form nanotubes, vesicles, thin films, columns, lamellar nanoribbons depending on the condition of self-assembly process. Unique characteristics of self-assembly of the amide dendrons are described. In addition, elucidation of the structural correlation between the building blocks and the assemblies, stabilization of assembled structure, and transformation of supramolecular assemblies by using external stimuli. Particular emphasis is placed on the formation of cyclodextrin-covered organic nanotubes derived from self-assembly of amide dendrons and their supramolecular transformation. Finally, unique biosensory characteristics of the self-assembled nanotubes will be discussed.