• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.16 no.4
• /
• pp.309-318
• /
• 1991

In this paper, the integrator used to reduce the error between the reference signal and response, and DC motor are constructed by bond graph. Then the model following servo controller which have the high adaptation with respect to inertia, disturbance and/or load variation in the speed control system of DC motor is designed by the bond graph, and then the usefullness of this modeling method is confirmed in operating analysis and design on controller.

• Journal of Power System Engineering
• /
• v.6 no.3
• /
• pp.71-77
• /
• 2002

In this study, a dynamic model of proportional pressure control valve using the bond graph and a predictive controller are presented in the form of dynamic matrix control which is concerned with a design method of digital controller for the electro hydraulic servo system. The bond graph can be utilized for all types of systems which involve power and energy, and it is applied to a propotional pressure control valve in this study. Recently, many researchers suggested that better control performance could be obtained by means of the predictive controls with future reference input, future control output and future control error. The Predictive controller is very practical because the controller can be easily applicable to a personal computer or a microprocessor. This study investigates through numerical simulations that hydraulic system with the predictive controller shows very good control performances.

• Advances in concrete construction
• /
• v.1 no.2
• /
• pp.137-149
• /
• 2013

The first part of this two-part paper discussed some basic considerations on bond strength and its effect on strain localization and plastic deformation capacity of cracked structural concrete, and analytically evaluated the impacts of the hardening behavior of reinforcing steel and concrete quality on the basis of the Tension Chord Model. This second part assesses the impacts of the most frequently encountered construction details of existing concrete structures which may not satisfy current design code requirements: bar ribbing, bar spacing, and concrete cover thickness. It further evaluates the impacts of the additional structure-specific features bar diameter and crack spacing. It concludes with some considerations on the application of the findings in practice and an outlook on future research needs.

• Computers and Concrete
• /
• v.9 no.3
• /
• pp.171-178
• /
• 2012

This paper presents numerical studies of stiff fiber pullout behaviors of fiber reinforced cementitious composites based on a progressive damage model. The ongoing debonding process is simulated. Interfacial stress distribution for different load levels is analyzed. A parametric study, including bond strength and the homogeneity index on the pullout behaviors is carried out. The numerical results indicate that the bond stress decreases gradually from loaded end to embedded end along fiber-cement interface. The debonding initially starts from loaded end and propagates to embedded end as load increasing. The embedded length and bond strength affect the load-loaded end displacement curves significantly. The numerical results have a general agreement with the experimental investigation.

• Structural Engineering and Mechanics
• /
• v.65 no.1
• /
• pp.1-7
• /
• 2018

This paper reviews the mechanical effects produced by reinforcement corrosion of prestressed concrete beams. Specifically, modifications in the bonding of the tendon to the concrete that reduce service life and load bearing capacity are studied. Experimental information gathered from previous works has been used for the theoretical analysis. Relationships between bond stress loss and reinforcement penetration in the concrete, and concrete external cracking were established. Also, it was analysed the influence that has the location of the area affected by corrosion on the loss magnitude of the initial prestress.

• The Journal of Natural Sciences
• /
• v.15 no.1
• /
• pp.47-56
• /
• 2005

The substituent dependence of geometric distortion through the two independent electronic substituent effects is analyzed for mono-substituted benzene derivatives of $C_{2v}$. Based on resonance structures, quantitative relationships expressing the resonance and field/inductive contribution terms in bond distortions are derived. The calculated field-effect parts of $C_{ipso}$_$C_{ortho}$ ring bonds increase and decrease compared to benzene for electropositive and electronegative substituents respectively. The nonbonded axial distance, $C_{ipso}$....$C_{para'}$ decreases for electronegative substituents and increases for electropositive substituents. As the electronegativity increases, the distance $C_{ortho}$....$C_{ortho'}$ increases. With the $\pi$-donors, $C_{meta}$....$C_{meta'}$ nonbonded distances are shorter compared to the ones of benzene, and for $\pi$-acceptors, the are longer. Our model based on valence bond approach predicts that the average bond length determined the area of ring, and the sum of the angles <$C_{ortho}$_$C_{ispo}$_$C_{ortho}$ and <$C_{meta}$_$C_{para}$_$C_{meta}$ determines the axial distance.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2000.04a
• /
• pp.853-858
• /
• 2000

According to the results of this research, Production of Fold Mortar Permanent - Form was found to be possible by Mortar. Th FP-Form (Fold Permanent-Form) mortar had compress strength 580kgf/$\textrm{cm}^2$. FP-Form model was made by the result of the first research. There was no minute-crack on beam form and the outer surface of form was very smooth, and those qualities it were made possible hand-mad by experiment. This study is about bond strength progress of FP-Form that developed for the form work rationalization and systematization. The result of this study follows; (1) Fluidity and strength development of mortar which used for FP-Form are satisfied (2) After study on getting good bond strength progress, inside-uneven type presents the better suitableness, and wire netting V-type presents the better shear strength.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.65 no.12
• /
• pp.2069-2074
• /
• 2016

This paper presents a methodology based on evolutionary optimization for simultaneously optimizing design parameters of controller and components of plant. Genetic programming(GP) based bond graph model generation is adopted to open-ended search for the plant. Also GP is applied to represent the controller with a unified method. The formulations of simultaneous plant-controller design optimization problem and the description of solution techniques based on bond graph are derived. A feasible solutions for a plant/controller design using the simultaneous optimization methodology is illustrated.

• Journal of Adhesion and Interface
• /
• v.21 no.1
• /
• pp.6-13
• /
• 2020

The objective of the current study is to characterize the long-term stability and efficacy of a structural adhesive assembly under static load. An apparatus was designed to be used in the Instron tensile test machine that would allow for real time modeling of the failure characteristics of an assembly utilizing a moisture- cure adhesive which was bonded to concrete. A regression model was developed that followed a linear - natural log function which was used to predict the expected life of the assembly. Evaluations at different curing times confirmed the structure was more robust with longer cure durations prior to loading. Finally, the results show that under the conditions the assembly was tested, there was only a small amount of inelastic creep and the regression models demonstrated the potential for a stable structure lasting several decades.

• Bulletin of the Korean Chemical Society
• /
• v.8 no.3
• /
• pp.144-145
• /
• 1987

The relative stability as function of geometry in the rigid tricyclopropylcarbinyl cations with varied bond angle (${\alpha}$) between the plane of cyclopropane ring and the bond connecting cyclopropane ring to cationic carbon was examined by $^{19}F$ nmr spectroscopy. 7-p-Fluorophenyltricyclo[2.2.2.$0^{2,6}$]octan-7-yl(4) and 8-p-fluorophenyltricyclo[3.2.2.$0^{2,7}$]nonan-8-yl cation (8) were generated from corresponding tertiary alcohols under stable ion conditions, and their $^{19}F$ chemical shifts were compared with those of model compounds such as 7-nortricyclyl cation (3) and tricyclo[3.3.1.$0^{2,7}$]octan-8-yl cation (7). Consequently, it is concluded that the varied orientation of bond angle (${\alpha}$) within in the bisected conformation does not affect degree of the charge delocalization into cyclopropane ring.