• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.11a
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• pp.117-120
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• 2005

The relationship between strain and applied potential was derived for composite actuators consisting single-wall carbon nanotubes (SWNTs) and conductive polymers (CPs). During deriving the relationship, an electrochemical ionic approach is utilized to formulate the electromechanical actuation of the composite film actuator. The results show that the well-aligned SWNTs composite actuator can give good actuation responses and high actuating forces available. The actuation is found to be affected by both SWNTs and CPs components and the actuation of SWNTs component has two kinds of influences on that of the CPs component: reinforcement at the positive voltage and abatement at the negative voltage. CNT/EAP was fabricated successfully using the chemical polymerization method.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1995.11a
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• pp.126-138
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• 1995

In order to study the gas interchangeability, a series of tests and analysis were conducted regarding to natural gas and gas mixture. Natural gas was selected as a reference and NG-LPG/Air mixture as a substitute gas. The major interest was placed on the determination of interchangeability limits for different mixing conditions. The parameters of Wobbe Index and Combustion Potential were employed in estimating the gas interchangeability, The limits obtained by analysis(AGA, WEAVER, KNOY, GILB) were compared with experimental results. The results estimated showed that the mixing limits of LPG/Air in proper conditions were found to vary with analysis and AGA is considered to be the most appropriate one.

• Proceedings of the IEEK Conference
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• 2000.07a
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• pp.310-313
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• 2000

This paper presents a new scheduling method for ILP processing called NHS(Novel Hybrid Scheduling). It concerns not only exploiting as much ILP as possible like other state-of-the-art scheduling scheme, but also choosing the most important instructions among many ready-to-execute instructions to processors in order to reduce the execution time under limited hardware resource. At the heart of NHS is a conception called CCP(Complex Critical Path), an extension of CP(Critical Path). By using CCP, compiler not only can get a global information of the whole program to extract ILP, but also can collecting data dependence information and control flow information. The paper also presents the simulation results, to date, of our attempts to study the NHS scheduling method. The results indicate good potential for this scheduling method.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.772-774
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• 2000

The objective of a cathodic protection system (CP) is to protect the buried metallic structure against the corrosion caused by chemical reaction between the buried structure and the surrounding medium, such as soil. This paper presents a boundary element application to determine the optimal impressed current densities in a cathodic protection system. The potential within the electrolyte is described by the Laplace's equation with nonlinear boundary conditions which are enforced based on experimentally determined electrochemical polarization curves. The optimal impressed current densities are determined in order to minimize the power supply for protection. The solution is obtained by using the conjugate gradient method in which the governing equations and the protecting conditions are taken into account by the penalty function method. Numerical example are presented to demonstrate the practical applicability of the proposed method.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.38 no.1
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• pp.182-187
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• 2015

Process capability indices (PCIs) have been widely used in manufacturing industries to provide a quantitative measure of process potential and performance to meet the specification limits on quality characteristics. The most of existing PCIs are concerned with a single variable. But, in many cases, people want to express a integrated PCI which includes a couple of sequential processes. In this paper, we analyzed the characteristics of system PCIs such as ${\bar{Cp}}(f)$, $SC_{pk}$, $SC_{psk}$, $C^T_{psk}(m)$ and $SC_{pm}(m)$.

• Corrosion Science and Technology
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• v.5 no.3
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• pp.112-116
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• 2006

This study has been conducted to monitor the corrosion rate of cathodically protected structure and corrosion inhibited system using multi-line thin-film electrical resistance (TFER) sensor in various environments. The field test data of TFER sensor for the corrosion monitoring of cathodically protected underground pipeline in soil environments and of corrosion inhibited gas heaters were also presented. The sensor was found to be a powerful method to commit the sensitive pick-up of small corrosion rate which can be observed in the cathodically protected and corrosion inhibited systems.

• ETRI Journal
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• v.41 no.2
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• pp.184-196
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• 2019

Wavelet packet modulation (WPM) is a multicarrier modulation (MCM) technique that has emerged as a potential alternative to the widely used orthogonal frequency-division multiplexing (OFDM) method. Because WPM has overlapped symbols, equalization cannot rely on the use of the cyclic prefix (CP), which is used in OFDM. This study applies linear minimum mean-square error (MMSE) equalization in the time domain instead of in the frequency domain to achieve low computational complexity. With a modest equalizer filter length, the imperfection of MMSE equalization results in subcarrier attenuation and noise amplification, which are considered in the development of a bit-loading algorithm. Analytical expressions for the bit error rate (BER) performance are derived and validated using simulation results. A performance evaluation is carried out in different test scenarios as per Recommendation ITU-R M.1225. Numerical results show that WPM with equalization-aware bit loading outperforms OFDM with bit loading. Because previous comparisons between WPM and OFDM did not include bit loading, the results obtained provide additional evidence of the benefits of WPM over OFDM.

• Clinical Pain
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• v.20 no.2
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• pp.86-92
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• 2021

Ultrasound imaging in clinical practice is one of the widely used diagnostic methods because there is no radiation risk, more cost- effective compared to MRI or CT, and possible to perform an intervention through fast real-time imaging. In order to increase the diagnostic value, the studies of contrast-enhanced ultrasound (CEUS) using an ultrasound contrast agent have been actively conducted since about 50 years ago and are being used clinically in vascularity and microcirculation of internal organs. Although ultrasound is actively used for the diagnosis and treatment of various diseases in musculoskeletal disorders, there are some limitations in diagnosing mild or small lesions, inflammatory reactions, or abnormalities at the molecular level. In this review, the principles, types, and research, and clinical applications of ultrasound contrast agents have been summarized and introduced. If we understand the characteristics of the ultrasound contrast agents and anatomical knowledge, as well as molecular changes, the ultrasound contrast agents are widely applied in musculoskeletal disorders and have tremendous potential for diagnosis and treatment.

• Clinical Pain
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• v.19 no.2
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• pp.111-115
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• 2020

We report a case of a healthy 38-year-old man presenting with insufficiency fracture of proximal tibia associated with unrecognized osteoporosis. Radiologic bone DEXA (Dual Energy X-ray Absorptiometry) assessment revealed osteoporosis, but the patient displayed no apparent risk factors for insufficiency fractures and osteoporosis except for a history of smoking. Following right proximal tibial open reduction and internal fixation, the patient commenced smoking cessation and began taking alendronate. The patient was treated for gait rehabilitation, which included quadriceps strengthening exercises and his condition improved with independent walking. This report highlights an unusual site of proximal tibial insufficiency fractures and the potential effect of smoking on low bone mineral density in a young male patient.

• Archives of Metallurgy and Materials
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• v.64 no.3
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• pp.899-905
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• 2019

In this study, molten salt electrorefining was used to recover indium metal from In-Sn crude metal sourced from indium tin oxide (ITO) scrap. The electrolyte used was a mixture of eutectic LiF-KF salt and InF₃ initiator, melted and operated at 700℃. Voltammetric analysis was performed to optimize InF₃ content in the electrolyte, and cyclic voltammetry (CV) was used to determine the redox potentials of In metal and the electrolyte. The optimum initiator concentration was 7 wt% of InF₃, at which the diffusion coefficients were saturated. The reduction potential was controlled by applying constant current densities of 5, 10, and 15 mA/cm² using chronopotentiometry (CP) techniques. In metal from the In-Sn crude melt was deposited on the cathode surface and was collected in an alumina crucible.