• Science of Emotion and Sensibility
• /
• v.20 no.1
• /
• pp.57-66
• /
• 2017

Emotional image quality optimization methodologies are investigated using technological image quality controls based on the eye tests of various image samples. The images are evaluated based on various contrast, lightness and saturation image quality metric tone curves. The order of importance to image quality enhancements is contrast, saturation and brightness. The slopes of emotional image qualities with respect to technical image quality metric changes are found to be composed of mathematical function modelling with nearly zero, intermediate and maximum slope regions in general, which can reflect well known log and saturated as well as conventional reverse U shape natures. Image quality improvements are analyzed not only with just single but also with multiple image quality metrics. To ease the unified image quality metric analysis and control, a new function is presented to utilize both the newly found and conventional emotional image quality behaviors. It is found that the overall image quality enhancement can be realized only in a few limited cases of multiple image quality metric controls. It is also found that the kinds of image quality enhancement methodologies are not strongly dependent on image contents (genre).

• Proceedings of the KSME Conference
• /
• 2007.05b
• /
• pp.2250-2254
• /
• 2007

Comprehensive analytical models focusing on the anode water loss, the cathode flooding, water equilibrium, and water management strategy are developed for polymer electrolyte fuel cells. Analytical solutions presented in this study are compared with two-dimensional computational results and shows a good agreement in predicting those critical characteristics of water. General features of water concentration profile as a function of membrane thickness and current density are presented to illustrate the net effect of the back-diffusion of water from the cathode to anode and the water production by the cathode catalytic reaction on water transport over a fuel cell domain. As one of practical applications, the required humidity level of feed streams for full saturation at the channel outlets are investigated as a function of the physical operating condition. These analytical models can provide good understanding on the characteristic water

• 제어로봇시스템학회:학술대회논문집
• /
• 1997.10a
• /
• pp.732-735
• /
• 1997

Variable Structure Controller(VSC) is usually known to have robustness to bounded exogenous disturbances. The robustness is attributed to the discontinuous term in the control input. However, this discontinuous term also causes an undesirable effect called chattering. To alleviate chattering, a hybrid controller consisting of VSC and Fuzzy Logic Controller(FLC) is proposed, which belongs to the category of Fuzzy Sliding Mode Controller(FSMC). The role of FLC in FSMC is to replace a fixed gain of a discontinuous term with a time-varying one based on a specified rule base. The characteristics of proposed controller are shown to be similar to those of VSC with a saturation function instead of sign function. The only remarkable difference is the nonlinearity whose form can be adjusted by free parameters, normalize gain, denormalize gain, and membership functions. Applied to AC servo motor, the proposed controller is compared with VSC in a regulation problem as well as a speed tracking problem. The simulation results show a substantial chatter reduction.

• Journal of the Korean Society for Precision Engineering
• /
• v.6 no.2
• /
• pp.30-39
• /
• 1989

Variable structure control (VSC) systems control the state vectors using sliding regime (SR) constructed switching logic, switching plane and control law. Saturation function switching logic is used to improve the drawback which occurs in traditional sign function switching logic. Switching plane with time-varying parameter is proposed to improve the drawback which occurs in switching plane with constant parameter and it is suggested the control law which has time-varying parameter. The stability of VSC system controlled by proposed time-varying SR is discussed, and the good control behavior was shown through computer simulation using proposed SR.

• The Korean Journal of Physiology
• /
• v.26 no.1
• /
• pp.37-44
• /
• 1992

The encapsulation of the Purified bovine hemoglobin with Phospholipids obtained from egg folk was performed using a rotary vacuum evaporator. The prepared Hb-containing liposome (hemosome) had good properties as artificial red blood cell. The shape and size of the hemosomes were measured by a phase contrast microscope and image analyzer. The function of the hemosome as oxygen carrier was tested by measuring oxygen saturation curve with blood gas analyzer and infusing it into rats. The prepared hemosome was 1.184 + 0.423 ${\mu}m$ in diameter and round in shape. $P_{50}$ value of the hemosome solution was 28 mmHg. The synthesized red cells seem to function as oxygen carrier, because the severely bled rats were prolonged in their life by transfusion of the hemosome solution containing bovine hemoglobin.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.10 no.4
• /
• pp.1846-1863
• /
• 2016

High dynamic range (HDR) images can present the perfect real scene and rich color information. A commonly encountered problem in practical applications is how to well visualize HDR images on standard display devices. In this paper, we propose a multi-scale decomposition method using guided filtering for HDR image tone mapping. In our algorithm, HDR images are directly decomposed into three layers：base layer, coarse scale detail layer and fine detail layer. We propose an effective function to compress the base layer and the coarse scale detail layer. An adaptive function is also proposed for detail adjustment. Experimental results show that the proposed algorithm effectively accomplishes dynamic range compression and maintains good global contrast as well as local contrast. It also presents more image details and keeps high color saturation.

• Proceedings of the KIEE Conference
• /
• 1987.11a
• /
• pp.203-206
• /
• 1987

$Ga_{1-x}Al_xAs$ solar cells have been fabricated by LPE and characterized as a function of operating temperature from $25^{\circ}C$ to $l30^{\circ}C$. Open circuit voltage decreases linearly with increasing temperature by $1.4mv/^{\circ}C$, while degradation of silicon solar cells is about $2.2-2.5\;mv/^{\circ}C$. Experimental results regarding to GaAS solar cells, such as saturation current, ideality factors and fill factors are characterized as a function of operating temperature.

• Proceedings of the KSME Conference
• /
• 2001.06b
• /
• pp.664-669
• /
• 2001

Continuous-time controller design is proposed using feedback system identification in frequency domain. System stability imposed by a new controller is checked in the function of a conventional closed-loop system, instead of a poorly modeled plant due to non-linearity and disturbance as well as unstable components, etc. The stability of the system is evaluated in view of Nyquist stability. All the equations are formulated in the framework of the discrete-time system. Simulation results are shown on the plant with input saturation and DC disturbance.

• Journal of Institute of Control, Robotics and Systems
• /
• v.4 no.2
• /
• pp.141-150
• /
• 1998

This paper presents a dynamical anti-reset windup (ARW) compensation method for saturating control systems with multiple controllers and/or multiloop configuration. By regarding the difference of controller states in the absence and presence of saturating actuators as an objective function, the dynamical compensator which minimizes the objective function is derived in an integrated fashion. The proposed dynamical compensator is a closed form of plant and controller parameters. The resulting dynamics of compensated controller reflects the linear closed-loop system. The proposed method guarantees total stability of the resulting system. The effectiveness of the proposed method is illustrated by applying it to a servo motor control system. The paper is an extension of the results in Park and Choi[1].

• Journal of Magnetics
• /
• v.18 no.1
• /
• pp.1-4
• /
• 2013

Structural and magnetic properties of $Fe_{50}Mn_{50}$ nanocrystalline alloys prepared by the mechanical alloying technique (using commercial Fe and Mn powders as the precursors) are studied as a function of milling time, 1 hr to 48 hrs. The nano-crystallite size and shape are examined by using scanning electron microscopy (SEM). The effect of milling time on structural characterization was investigated using X-ray diffractometer (XRD) and extended X-ray absorption fine structure spectroscopy (EXAFS). Both XRD and EXAFS studies showed that the alloying process should be completed after 36 hrs milling. Concerning the magnetic behavior, the data obtained from superconducting quantum interference devices (SQUID) exhibited both magnetic saturation ($M_s$) and coercivity ($H_c$) depend strongly on the milling time, which are related to the changes in the crystallite size and magnetic dilution.