• Smart Structures and Systems
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• v.11 no.3
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• pp.315-329
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• 2013

The construction of an experimental nonlinear structural model with little cost and unlimited repeatability for vibration control study represents a challenging task, especially for material nonlinearity. This paper reports the design, analysis and vibration control of a nonlinear structural experiment platform with adjustable hinges. In our approach, magnetorheological rotary brakes are substituted for the joints of a frame structure to simulate the nonlinear material behaviors of plastic hinges. For vibration control, a separate magnetorheological damper was employed to provide semi-active damping force to the nonlinear structure. A dynamic neural network was designed as a state observer to enable the feedback based semi-active vibration control. Based on the dynamic neural network observer, an adaptive fuzzy sliding mode based output control was developed for the magnetorheological damper to suppress the vibrations of the structure. The performance of the intelligent control algorithm was studied by subjecting the structure to shake table experiments. Experimental results show that the magnetorheological rotary brake can simulate the nonlinearity of the structural model with good repeatability. Moreover, different nonlinear behaviors can be achieved by controlling the input voltage of magnetorheological rotary damper. Different levels of nonlinearity in the vibration response of the structure can be achieved with the above adaptive fuzzy sliding mode control algorithm using a dynamic neural network observer.

• Journal of The Korean Society of Agricultural Engineers
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• v.59 no.2
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• pp.19-27
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• 2017

Recently, the hydrological model Soil Water Assessment Tool (SWAT) has been applied in many watersheds in South Korea. This study estimated parameters in SWAT for calibrating streamflow in long-term drought periods. Therefore, we focused on the continuous severe drought periods 2014~2015, and understand the model calibrated parameters. The SWAT was applied to a $366.5km^2$ Gongdo watershed by using 14 years (2002~2015) daily observed streamflow (Q) including two years extreme drought period of 2014~2015. The 9 parameters of CN2, CANMX, ESCO, SOL_K, SLSOIL, LAT_TIME, GW_DELAY, GWQMN, ALPHA_BF were selected for model calibration. The SWAT result by focusing on 5 normal years (2002~2006) calibration showed the 14 years average Nash-Sutcliffe model efficiency (NSE) for Q and 1/Q with 0.78 and 0.58 respectively. On the other hand, the 14 years average NSEs of Q and 1/Q by focusing on 2 drought years (2014~2015) calibration were 0.86 and 0.76 respectively. Thus, we could infer that the SWAT calibration trial by focusing on drought periods data can be a good approach to calibrate both high flow and low flow by controlling the 9 drought affected parameters.

• Journal of Biomedical Engineering Research
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• v.38 no.1
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• pp.1-8
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• 2017

The successful synthesis of hyaluronic acid micro-threads is very promising approach for the broad application in tissue engineering such as dermal fillers. Because hyaluronic acid has the excellent biocompatibility and ability to maintain the moisture of up to several hundred times its own weight. In order to generate the hyaluronic acid micro-threads in microfluidic system, we employed two-phase flow microfluidic chip to make a rapid synthesis of the hyaluronic acid hydrogel. Hyaluronic acid was mixed with 0.02N NaOH solution and 1, 4-Butanediol diglycidyl ether (BDDE) solution and then injected into core channel. The ethanol was used for the 3-dimensional micro-thread formation in sheath channel. We manipulated the diameter of HA micro-threads using controlling of flow rates in microfluidic chip, and showed the feasibility of immobilization in HA micro-threads with florescent substances. Also, the generated HA micro-threads were evaluated and showed the suitable properties with tensile strength, bending property, and swelling profiles for dermal fillers. As a result, we suggested an innovative method for microfluidic chip-based HA micro-threads which could safely be applied as dermal filler in tissue engineering.

• Journal of KIISE:Software and Applications
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• v.36 no.12
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• pp.1028-1033
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• 2009

This paper presents a real-time hand gesture recognition approach for controlling a computer. We define hand gestures as continuous hand postures and their movements for easy expression of various gestures and propose a Two-layered Bayesian Network (TBN) to recognize those gestures. The proposed method can compensate an incorrectly recognized hand posture and its location via the preceding and following information. In order to vertify the usefulness of the proposed method, we implemented a Virtual Mouse interface, the gesture-based interface of a physical mouse device. In experiments, the proposed method showed a recognition rate of 94.8% and 88.1% for a simple and cluttered background, respectively. This outperforms the previous HMM-based method, which had results of 92.4% and 83.3%, respectively, under the same conditions.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.304-304
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• 2006

The possibility to develop optoelectronic devices with improved properties by controlling the degree of organization at the molecular level of organic materials has been driving the design of new ${\pi}-conjugated$ systems. In particular, the organization by self-assembling processes (${\tilde{\Box}}{\d{\Box}}}$ interactions, hydrogen bonding) of well-defined oligomeric systems such as disubstituted oligothiophene derivatives has been demonstrated as a promising approach to conjugated materials with a high degree of structural order of the constituent building blocks. The self-organization of conjugated building blocks in solution or on surfaces, leading to the construction of nanoscopic and mesoscopic architectures, represents a starting point for the construction of molecular electronics or even circuits, through surface patterning with nanometer-sized objects.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.39 no.1
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• pp.27-30
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• 2013

Dental implantation in the mandibular anterior region is considered a safe and reliable surgical procedure. On the other hand, several articles have reported that inadvertent hemorrhage of the sublingual artery can result in life-threatening airway obstruction. Surgical ligation under intubation or tracheostomy is the most widely used approach for controlling mouth floor bleeding in this highly vascular region. Nonetheless, surgically exploring the bleeding focus is difficult because of anatomical distortion followed by widespread edema and swelling. Since swelling of the mouth floor advances quickly, timely management is essential for favorable postoperative outcome. This paper reports a case of immediate hemorrhage control with angiographic embolization to perform rapid hemostasis before the ongoing swelling causes airway obstruction. Less invasive, angiographic embolization can prevent neurovascular damage during a surgical exploration of injured vascular structures on the mouth floor.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.2
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• pp.71.2-71.2
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• 2014

processes at the origin of the star formation in the galaxies over the last 10 billions years. While it was proposed in the past that merging of galaxies has a dominant role to explain the triggering of the star formation in the distant galaxies having high star formation rates. In the opposite, more recent studies revealed scaling laws linking the star formation rate in the galaxies to their stellar mass or their gas mass. The small dispersion of these laws seems to be in contradiction with the idea of powerful stochastic events due to interactions, but rather in agreement with the new vision of galaxy history where the latter are continuously fed by intergalactic gas. I was especially interested in one of this scaling law, the relation between the star formation (SFR) and the stellar mass (M*) of galaxies, commonly called the main sequence of star forming galaxies. I have studied this main sequence, SFR-M*, in function of the morphology and other physical parameters as the radius, the colour, the clumpiness. The goal was to understand the origin of the sequence's dispersion related to the physical processes underlying this sequence in order to identify the main mode of star formation controlling this sequence. This work needed a multi-wavelength approach as well as the use of galaxies profile simulation to distinguish between the different galaxy morphological types implied in the main sequence.

• Research in Community and Public Health Nursing
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• v.12 no.2
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• pp.317-328
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• 2001

The purposes of this study were to develop the empowerment education program, to describe the experiences of diabetes patient's empowerment process and to develop a theoretical model of the diabetes patient's empowerment process. Method 1. : The development of the empowerment program for the diabetes patients: The strategies of the empowerment education program were enhancement of problem - solving, decision making, self-efficacy, self-control. participation and mutual support. Method 2. : According to the grounded theory methodology of Strauss and Corbin, the qualitative data was collected with in depth interviews and participants observations until its saturation when the 25 consented subjects were participating and interacting with the other subjects in the empowerment education program. Results: With the analysis of the data, 29 categories were generated. The core category generated, which was a central phenomenon of the empowerment process, was named powerlessness. The intervening conditions facilitating or impeding the empowerment process were discovered as supportive systems through the participation of group meeting, problem solving dialogue, and the knowledge deficit of self-care. The action/interaction strategies were developed as the paricipating, dialoguing, questioning, supporting system, self-controlling, self efficacy, enhancing self-esteem. stress relaxing and instillation of hope.

• Journal of Korea Game Society
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• v.9 no.1
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• pp.127-134
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• 2009

This paper presents a motion generation technique for arbitrary morphologies with the user defined correspondences between joints. Users can define the controlling part in the source character and the part to be controlled in the target character in our system. To remove the restriction in the morphology of the target character, we use the pair of example posture sets. In our system, in order to provide the correspondence regardless of the number of joints, the deformed part in the target character is simplified into the direction vector. The final postures are then generated with the weighted sum of the examples. Our experimental results demonstrate that our approach can generate motions for various target characters and can control the user defined joints in real-time.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.51 no.2
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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.