• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.3
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• pp.113-121
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• 2011

Rollover accident is one of the serious traffic accident and rollover accident takes high portion of all accident. The most common type of rollover is a tripped rollover which occupy 95% of all type of single-vehicle rollover. Tripped rollover occurs when a vehicle leaves normal road way and tripped by loose gravel, soil of fixed object such as guard rail, curbs and ditches. And the rest of the type of rollover is un-tripped rollover. An un-tripped rollovers that occurs during high-speed collision avoidance maneuvers. In this paper, presents the explanation of the un-tripped rollover test method and procedure, additionally this paper deals with various occurrence in the un-tripped test such as occurring excessive tire camber in the un-tripped test, tire side-wall contact with road surface and roll oscillation. And this paper analyzes the analysis of the roll rate amplitude in specific frequency through the FFT (Fast Fourier Transform) and the roll angle at the steering reverse timing which is the Fishhook test roll rate feedback time. Finally, this paper analyzes the relations between the estimated steady state roll gain and rollover stability.

• Korean System Dynamics Review
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• v.9 no.1
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• pp.155-170
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• 2008

The purpose of this study was to develop a system dynamics model for management of glucose metabolism disorders that demonstrated dynamic relationships between insulin and plasma glucose levels over the time. The model was developed to 1) represent the physiology of glucose metabolism for an normal adult subject, 2) to draw causal loop diagram that demonstrate feedback systems of glucose regulation in normal condition and pathologic condition of the type 2 diabetes, 3) to develop an interactive computer simulation model for management of glucose metabolism disorders. The simulation results showed the plasma glucose level for normal persons varied from 75 to 140 which was consistent with clinical findings. As an example for patients we selected a case which varied from 110 to 310. Two types of interventions were chosen to review the model; meal control and insulin administration. The simulation results for those cases also matched well with clinical findings. The developed model can be used as an effective educational tool for patients to develop healthy lifestyle choices. The results also provide a blueprint for health providers to maintain normal blood glucose levels in diabetes patients.

• Korean System Dynamics Review
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• v.15 no.3
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• pp.81-104
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• 2014

This study aimed to suggest the directions for the landscape protection of Sindu-ri coastal dune based on its ecological system. The study investigated ecological systems of the coastal dune followed by damage causes of coastal dune according to the land use change, and landscape value of coastal dune in the study area. In order to construct causal-effect feedback loop, systems thinking was performed. Result of this study showed that the area of coastal dune and the amount of sand are maintained by the interaction with sand beach while they are affected by wind direction, wind speed, and dune plants. It was also found that the changes of land use pattern, increasing commercial area, and planted windbreak forest damaged to the coastal dune. In addition, size of coastal dune and growing number of dune plants increased landscape value of coastal dune and tourist draw. However increasing tourists have constantly affected land use changes and have damaged to coastal dune area. In sum, planning for land use regulation, rest-year system areas, promotion and education for coastal dune, dune plants protection, and windbreak management should be taken into account for landscape protection in coastal dune.

• Journal of Institute of Control, Robotics and Systems
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• v.9 no.1
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• pp.10-21
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• 2003

During seek operation in disk drives, the recording head is moved toward desired track by seek servo controller and then is settled onto the center of the desired track by settling servo controller. If the head speed at the start of settling servo control is not slow, it may produce overshoot relative to the center of track and thus extend the settling time. The degradation in settling performance will be more severe as the track width becomes smaller for higher density of data storage. We design a new settling servo controller for minimizing settling time based on the pole-zero cancellation. In order to cancel slow poles in settling response, we apply discrete pulse signals to the system in addition to the state feedback control. For exact pole-zero cancellation, we consider the dynamics of power amplifier used for actuator current regulation and the effects of delay in control action. In addition, we present system parameter identification algerian for the robustness of our controller to system parameter variation. In order to demonstrate the practical use of our controller, we present experimental results obtained by using a commercially available disk drive.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.3
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• pp.62-68
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• 2006

In this paper, an adaptive input-output linearization and zero dynamics control of three phase AC/DC converter are proposed. For achieving output do voltage regulation with unity power factor, the q-axis current of the rotating d-q frame is regulated to zero and the output do voltage is controlled to track a given reference voltage $V_r$. The proposed scheme is robust to the parametric uncertainty md load current of the converter due to the adaptation process. The simulation results are presented to illustrate the performance and feasibility of the proposed control scheme.

• Biomedical Science Letters
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• v.22 no.3
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• pp.107-114
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• 2016

Maintenance of fasting blood glucose levels is important for glucose homeostasis. Disruption of feedback mechanisms are a major reason for elevations of glucose level in blood, which is a risk factor for type 2 diabetes mellitus that is mainly caused by malfunction of pancreatic beta-cell and insulin. The fasting blood glucose level has been known to be influenced by genetic and environmental factors. Mitochondria have many functions for cell survival and death: glucose metabolism, fatty acid oxidation, ATP generation, reactive oxygen species (ROS) metabolism, calcium handling, and apoptosis regulation. In addition to these functions, mitochondria change their morphology dynamically in response to multiple signals resulting in fusion and fission. In this study, we aimed to examine association between fasting blood glucose levels and variants of the genes that are reported to have functions in mitochondrial dynamics, fusion and fission, using a cohort study. A total 416 SNPs from 36 mitochondrial dynamics genes were selected to analyze the quantitative association with fasting glucose level. Among the 416 SNPs, 4 SNPs of PRKACB, 13 SNPs of PPP3CA, 6 SNPs of PARK2, and 3 SNPs of GDAP1 were significantly associated. In this study, we were able to confirm an association of mitochondrial dynamics genes with glucose levels. To our knowledge our study is the first to identify specific SNPs related to fasting blood glucose level.

• BMB Reports
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• v.42 no.8
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• pp.523-528
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• 2009

Phosphomannose isomerase (PMI) catalyzes the interconversion of fructose-6-phosphate and mannose-6-phosphate in the extracellular polysaccharide (EPS) synthesis pathway. The gene encoding PMI in Sphingomonas chungbukensis DJ77 was cloned and expressed in E. coli. The pmi gene is 1,410 nucleotides long and the deduced amino acid sequence shares high homology with other bifunctional proteins that possess both PMI and GDP-mannose pyrophosphorylase (GMP) activities. The sequence analysis of PMI revealed two domains with three conserved motifs: a GMP domain at the N-terminus and a PMI domain at the C-terminus. Enzyme assays using the PMI protein confirmed its bifunctional activity. Both activities required divalent metal ions such as $Co^{2+}$, $Ca^{2+}$, $Mg^{2+}$, $Ni^{2+}$ or $Zn^{2+}$. Of these ions, $Co^{2+}$ was found to be the most effective activator of PMI. GDP-D-mannose was found to inhibit the PMI activity, suggesting feedback regulation of this pathway.

• Journal of Power Electronics
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• v.14 no.4
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• pp.704-711
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• 2014

This paper proposes a combined fuzzy adaptive sliding-mode voltage controller (FASVC) for a three-phase UPS inverter. The proposed FASVC encapsulates two control terms: a fuzzy adaptive compensation control term, which solves the problem of parameter uncertainties, and a sliding-mode feedback control term, which stabilizes the error dynamics of the system. To extract precise load current information, the proposed method uses a conventional load current observer instead of current sensors. In addition, the stability of the proposed control scheme is fully guaranteed by using the Lyapunov stability theory. It is shown that the proposed FASVC can attain excellent voltage regulation features such as a fast dynamic response, low total harmonic distortion (THD), and a small steady-state error under sudden load disturbances, nonlinear loads, and unbalanced loads in the existence of the parameter uncertainties. Finally, experimental results are obtained from a prototype 1 kVA three-phase UPS inverter system via a TMS320F28335 DSP. A comparison of these results with those obtained from a conventional sliding-mode controller (SMC) confirms the superior transient and steady-state performances of the proposed control technique.

• Korean System Dynamics Review
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• v.17 no.3
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• pp.91-120
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• 2016

This study explores hedge fund characteristics that affect hedge fund performance, namely, fund size, fund age, and performance fee. Previous studies have examined relationships between hedge fund characteristics and fund performance using singular and static thinking to report inconsistent findings without providing full understanding of the causal relationships among variables. To identify that comprehensive causal relationships between hedge fund characteristics and hedge fund performance, this research applies the system dynamics perspective, which allowed demonstration of the interactions within the overall system beyond the singular causal relationships between hedge fund characteristics and performance found in existing traditional research. This study contributes to existing literature in the following ways. First, it overcomes the limitations of singular research methodologies by looking at the integrated system of hedge fund characteristics and fund performance from a bird's eye view based on their dynamic feedback relationships. Second, policy suggestions in terms of regulation and education are presented as growth strategies for the sustainable development of the Korean hedge fund market.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.4
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• pp.587-595
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• 2002

Recent trend changes a criterion for evaluation of humors that environmental problems are raised as a global issue. Burners with higher thermal efficiency and lower oxygen in the exhaust gas, evaluated better. To comply with environmental regulations, burners must satisfy the NO/sub x/ and CO regulation. Consequently, 'good burner'means one whose thermal efficiency is high under the constraint of NO/sub x/ and CO consistency. To make existing burner satisfy recent criterion, it is highly recommended to develop a feedback control scheme whose output is the consistency of NO/sub x/ and CO. This paper describes the development of a real time flame diagnosis technique that evaluate and diagnose the combustion states, such as consistency of components in exhaust gas, stability of flame in the quantitative sense. In this paper, it was proposed on the flame diagnosis technique of burner using Neuro-Fuzzy algorithm. This study focuses on the relation of the color of the flame and the state of combustion. Neuro-Fuzzy loaming algorithm is used in obtaining the fuzzy membership function and rules. Using the constructed inference algorithm, the amount of NO/sub x/ and CO of the combustion gas was successfully inferred.