• Molecules and Cells
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• 제26권2호
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• pp.200-205
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• 2008

The mitogen-activated protein kinase (MAPK) signaling pathway is activated in response to extracellular stimuli and regulates various activities in eukaryotic cells. Following exposure to stimuli, MAPK is known to be activated via dual phosphorylation at a conserved TxY motif in the activation loop; both threonine and tyrosine residues are phosphorylated by an upstream kinase. However, the mechanism underlying dual phosphorylation is not clearly understood. In the budding yeast Saccharomyces cerevisiae, the Hog1 MAPK mediates the high-osmolarity glycerol (HOG) signaling pathway. Tandem mass spectrometry and phosphospecific immunoblotting were performed to quantitatively monitor the dynamic changes occurring in the phosphorylation status of the TxY motif of Hog1 on exposure to osmotic stress. The results of our study suggest that the tyrosine residue is preferentially and dynamically phosphorylated following stimulation, and this in turn leads to the dual phosphorylation. The tyrosine residue was hyperphosphorylated in the absence of a threonine residue; this result suggests that the threonine residue is critical for the control of signaling noise and adaptation to osmotic stress.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2009년도 추계학술대회 논문집
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• pp.855-863
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• 2009

In this study, a beam-column junction type damper is proposed which saves the inner and outer space for the installation of damping devices and allows easy adjustment of control performance The result of the numerical analysis indicated that the displacement response and base shear of a single degree of freedom system by seismic load, El Centro 1940 was reduced with yield moment of the joint hinge and the specific yield moment ratio $\delta$ of the joint hinge existed for the optimal seismic performance. In addition, the dynamic nonlinear characteristics, effects of yielding and dependence of natural period of bi-linear system with the junction type damper is identified. The analysis of multi-degree of freedom system showed that responses of the controlled structures was reduced significantly as the number of a story increases and yield moment ratio decreases when the system is excited by seismic load and sine wave. On top of that, it was also observed that energy dissipation at the joint connected with the dampers was remarkable during excitation.

• Wind and Structures
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• 제12권4호
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• pp.333-347
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• 2009

Many tower-supported steel stacks have been constructed in Japan, primarily for economic reasons. However the dynamic behavior of these stacks under a strong wind is not well known and the wind load design standard for this type of a stack has not yet been formulated. In light of this situation, we carried out wind response observation of an operating tower-supported steel stack with and without a tuned-mass damper. The observation revealed the performance of the tuned-mass damper installed on the stack in order to control the wind-induced vibration. Based on the observed data, we performed a wind tunnel test of a specimen of the stack. In this paper we report the results of the wind tunnel test and some comparisons with the results of observation. Our findings are as follows: 1) the tuned-mass damper installed on the specimen in the wind tunnel test worked as well as the one on the observed stack, 2) the amplitude of the vortex-induced vibration of the specimen corresponded approximately to that of the observed stack, and 3) correlation between Scruton number and reduced amplitude, y/d, (y is amplitude, d is diameter) was confirmed by both the wind tunnel test and the observed results.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.787-790
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• 1997

This paper proposes a method which selects essential elements in a human evaluation model using the Choquet integral based on fuzzy measures, and applies the model to the evaluation of human interface. Three kinds of concepts are defined to select essential elements. Increment Degree implies the increment degree from fuzzy measures of composed elements to the fuzzy measure of a combined element. Average of Increment Degree of an element means the relative possibility of superadditivity of the fuzzy measure of each combined element. Necessity Degree means the selection degree of each combined element as a result of the human evaluation. A task experiment, which consists of a static work and two dynamic works, is performed by the use of some human interfaces. In the experiment, (1) a warning sound which gives an attention to subjects, (2) a color vision which can be distinguished easily or not, (3) the size of working area and (4) a response of confirmation that is given from an interface, are considered as human interface elements. Subjects answer the questionnaire after the experiment. From the data of the questionnaire, fuzzy measures are identified and are applied to the proposed model. Effectiveness of the proposed model is confirmed by the comparison of human interface elements extracted from the proposed model and those from the questionnaire.

• Nuclear Engineering and Technology
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• 제52권9호
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• pp.2017-2024
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• 2020

In this study, a fractional order proportional integral derivative (FOPID) controller is designed to create the reference power trajectory and to conquer the uncertainties and external disturbances. A fractional nonlinear model was utilized to describe the nuclear reactor dynamic behaviour considering thermal-hydraulic effects. The controller parameters were tuned using optimization method in Matlab/Simulink. The FOPID controller was simulated using Matlab/Simulink and the controller performance was evaluated for Hard variation of the reference power and compared with that of integer order a proportional integral derivative (IOPID) controller by two models of fractional neutron point kinetic (FNPK) and classical neutron point kinetic (CNPK). Also, the FOPID controller robustness was appraised against the external disturbance and uncertainties. Simulation results showed that the FOPID controller has the faster response of the control attempt signal and the smaller tracking error with respect to the IOPID in tracking the reference power trajectory. In addition, the results demonstrated the ability of FOPID controller in disturbance rejection and exhibited the good robustness of controller against uncertainty.

• Structural Engineering and Mechanics
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• 제66권5호
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• pp.637-648
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• 2018

When the centers of mass and stiffness of a building do not coincide, the structure experiences torsional responses. Such systems can consist of the underlying soil and the super-structure. The underlying soil may modify the earthquake input motion and change structural responses. Specific effects of the input motion shall also not be ignored. In this study, seismic demands of asymmetric buildings considering soil-structure interaction (SSI) under near-fault ground motions are evaluated. The building is modeled as an idealized single-story structure. The soil beneath the building is modeled by non-linear finite elements in the two states of loose and dense sands both compared with the fixed-base state. The infinite boundary conditions are modelled using viscous boundary elements. The effects of traditional and yield displacement-based (YDB) approaches of strength and stiffness distributions are considered on seismic demands. In the YDB approach, the stiffness considered in seismic design depends on the strength. The results show that the decrease in the base shear considering soft soil induced SSI when the YDB approach is assumed results only in the center of rigidity to control torsional responses. However, for fixed-base structures and those on dense soils both centers of strength and rigidity are controlling.

• Smart Structures and Systems
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• 제14권6호
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• pp.1221-1245
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• 2014

Real-time hybrid simulation (RTHS) is a promising cyber-physical technique used in the experimental evaluation of civil infrastructure systems subject to dynamic loading. In RTHS, the response of a structural system is simulated by partitioning it into physical and numerical substructures, and coupling at the interface is achieved by enforcing equilibrium and compatibility in real-time. The choice of partitioning parameters will influence the overall success of the experiment. In addition, due to the dynamics of the transfer system, communication and computation delays, the feedback force signals are dependent on the system state subject to delay. Thus, the transfer system dynamics must be accommodated by appropriate actuator controllers. In light of this, guidelines should be established to facilitate successful RTHS and clearly specify: (i) the minimum requirements of the transfer system control, (ii) the minimum required sampling frequency, and (iii) the most effective ways to stabilize an unstable simulation due to the limitations of the available transfer system. The objective of this paper is to establish a stability switch criterion due to systematic experimental errors. The RTHS stability switch criterion will provide a basis for the partitioning and design of successful RTHS.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.63.2-63.2
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• 2015

Controlling and sensing spin states of magnetic molecules such as metallo-porphyrins at the single molecule level is essential for spintronic molecular device applications. Axial coordinations of diatomic molecules to metallo-porphyrins also play key roles in dynamic processes of biological functions such as blood pressure control and immune response. However, probing such reactions at the single molecule level to understand their physical mechanisms has been rarely performed. Here we present on our single molecule association and dissociation experiments between diatomic and metallo-porphyrin molecules on Au(111) describing its adsorption structures, spin states, and dissociation mechanisms. We observed bright ring shapes in NO adsorbed metallo-porphyrin compelxes and explained them by considering tilted binding and precession motion of NO. Before NO exposure, Co-porphryin showed a clear zero-bias peak in scanning tunneling spectroscopy, a signature of Kondo effect in STS, whereas after NO exposures it formed a molecular complex, NO-Co-porphyrin, that did not show any zero-bias feature implying that the Kondo effect was switched off by binding of NO. Under tunneling junctions of scanning tunneling microscope, both positive and negative energy pulses. From the observed power law relations between dissociation rate and tunneling current, we argue that the dissociations were inelastically induced with molecular orbital resonances. Our study shows that single molecule association and dissociation can be used to probe spin states and reaction mechanisms in a variety of axial coordination between small molecules and metallo-porphyrins.

• 한국구조물진단유지관리공학회 논문집
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• 제8권2호
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• pp.221-230
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• 2004

본 논문에서는 지진하중 작용시, 점탄성 감쇠기 및 면진장치를 설치한 다층 철골 모멘트 저항 골조의 동적응답을 해석적으로 규명하였다. 본 연구의 목적은 구조해석을 수행하여 최대 층간변위 및 최대응력법에 의해 효율적인 점탄성 감쇠기의 위치를 결정하는 것이다. 또한, 효율적인 진동 제어방법을 모색하기 위하여 점탄성 감쇠기 및 납삽입고무베어링형 면진장치에 의한 제어효과를 부재력, 조합응력, 그리고 구조물의 고유주기 등을 이용하여 상호 비교 분석하였다.

• International Journal of Aeronautical and Space Sciences
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• 제11권2호
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• pp.145-153
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• 2010

In this work, the comprehensive structural dynamics codes including DYMORE and CAMRAD II are used to validate the higher harmonic control aeroacoustic rotor test (HART) II data in descending flight condition. A total of 16 finite elements along with 17 aerodynamic panels are used for the CAMRAD II analysis; whereas, in the DYMORE analysis, 10 finite elements with 31 equally-spaced aerodynamic panels are utilized. To improve the prediction capability of the DYMORE analysis, the finite state dynamic inflow model is upgraded with a free vortex wake model comprised of near shed wake and trailed tip vortices. The predicted results on aerodynamic loads and blade motions are correlated with the HART II measurement data for the baseline, minimum noise and minimum vibration cases. It is found that an improvement of solution, especially for blade vortex interaction airloads, is achieved with the free wake method employed in the DYMORE analysis. Overall, fair to good correlation is achieved for the test cases considered in this study.