• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.457-462
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• 2006

This paper is concerned with the active vibration control experiment on cylindrical shell equipped with Macro Fiber Composite(MFC) actuators. The MFC actuators were glued to the cylindrical shell in circumferential directions. To verify the theoretical result, vibration test using impact hammer and accelerometer was carried out. It was found from experiments that theoretical result predicts experimental result to some extent. The positive position feedback controllers were designed and applied to the test article. It was observed that the resonant amplitude of the fundamental mode was reduced by 20dB thus achieving active vibration control. The active vibration control of the response subject to non resonant excitation has been of interest. We developed the combination of the positive position feedback controller which can cope with the fundamental mode and the positive position feedback controller which can counteract the external disturbance with non resonant frequency. It was found from experiments that the hybrid controller can suppress the vibration amplitude successfully.

• Communications of Mathematical Education
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• v.25 no.1
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• pp.207-219
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• 2011

The purpose of this article is to study characteristics of diabolical cube in geometric point of view, and to present educational materials and direction for efficient diabolical cube activities in gifted education upon systematical analysis of methods of finding solutions. We can apply inclusion-exclusion Method to find all possible combination of solutions in diabolical cube activities not as trial-and-error method but as analytical method. Through teacher's questions and problem posing in activities using diabolical cube, we systematically came up with most solution and case of all possible combinations be solution in classifying properties of pieces and combining selected pieces.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2007.05a
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• pp.19-32
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• 2007

A new generation of fiber-based papermaking chemicals were presented for the first time at the PTS Pulp Technology Symposium 2005, and then several articles were published in various magazine in Asia ("Paper Asia"), the US ("Pulp & Paper"), and Europe ("Wochenblatt fuel Papierfabrikation"). The information generated quite an interest in the paper industry. Extensive studies of these papermaking additives have been made recently, new information obtained, and the compounds have gained more recognition in the industry. The company J. Rettenmaier und Soehne developed of a group of fiber-based papermaking additives. They includ combination of fibers with sizing agents, starch, fluorochemicals, minerals, biocides and some others. This article presents in-depth study of the AKD modified micronized cellulose as an example of the fiber-based papermaking chemicals cocept. The material of the present paper is based mostly on the results of the pilot paper machine study at the Paper Research Institute PTS (Heidenau, Germany), and includes case studies from the mills, which used $ARBOCELPLUS^{(R)}-AKD$ compounds. It should be noted that the $ARBOCELPLUS^{(R)}$ compounds were not designed to replace traditional additives in paper industry. They should rather be used in those areas, where application of "normal" chemicals is especially problematic.

• Environmental Analysis Health and Toxicology
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• v.23 no.3
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• pp.143-164
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• 2008

Concern about perfluorinated compounds (PFCs) is growing nationally as well as globally. PFCs could be considered emerging POPs due to their environmentally persistent, bioaccumulative, and potentially harmful properties. Moreover. perfluoroalkylates (PFAs) such as PFOS and PFOA are reported to experience long-range transport (LRT) to the Arctic in spite of their low volatility and strong solubility. The possible pathways contributing to LRT have been proposed but are still in debate in combination with unclear source definition and uncertain physico-chemical properties. The environmental fate of PFCs is more complicated because of the presence of precursors that are degraded to PFAs and are extremely different from their daughters, PFAs. in physico-chemical properties. To what extent and through what pathways are human and wildlife exposed is determined by the environmental fate and distribution of PFCs. To define uncertainties in fate and distribution thus is critical to prevent erroneous policy and/or determination related with exposure and risk reduction. This article aimed to review controversy and/or uncertain issues for the environmental fate and distribution of PFCs and to prospect research topics necessary to dissolve uncertainties.

• Macromolecular Research
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• v.14 no.2
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• pp.155-165
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• 2006

The present article describes the experimental and theoretical observations on the formation of holographic, polymer-dispersed, liquid crystals and electrically switchable, photonic crystals. A phase diagram of the starting mixture of nematic liquid crystal and photo-reactive triacrylate monomer was established by means of differential scanning calorimetry (DSC) and cloud point measurement. Photolithographic patterns were imprinted on the starting mixture of LC/triacrylate via multi-beam interference. A similar study was extended to a dendrimer/photocurative mixture as well as to a single component system (tetra-acrylate). Theoretical modeling and numerical simulation were carried out based on the combination of Flory-Huggins free energy of mixing and Maier-Saupe free energy of nematic ordering. The combined free energy densities were incorporated into the time-dependent Ginzburg-Landau (Model C) equations coupled with the photopolymerization rate equation to elucidate the spatio-temporal structure growth. The 2-D photonic structures thus simulated were consistent with the experimental observations. Furthermore, 3-D simulation was performed to guide the fabrication of assorted photonic crystals under various beam-geometries. Electro-optical performance such as diffraction efficiency was evaluated during the pattern photopolymerization process and also as a function of driving voltage.

• Archives of Craniofacial Surgery
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• v.17 no.4
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• pp.202-205
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• 2016

Background: Packing after closed reduction of nasal fracture causes uncomfortable nasal obstruction in patients. We packed the superior meatus with synthetic polyurethane foam (SPF) to support the nasal bone, and packed the middle nasal meatus with a nasal airway splint (NAS) and SPF. The aim of this article is prospectively to compare the subjective patient discomfort of SPF (Nasopore Forte plus) packing alone and SPF with NAS. Methods: We compared the prospectively subjective patient discomfort of SPF packing alone (group A) and SPF with NAS (group B) via visual analog scale (VAS; 0, no symptom; 100, most severe symptom). Results: At first postoperative day group B showed significant lower scores in dry mouth, sleep disturbance, conversation difficulty. However at third postoperative day, VAS scores of each group had no statistically significant differences. Moreover at fifth postoperative day group A had statistically significant lower scores for nasal pain, dry mouth than the group B. Conclusion: Combination method of using NAS and SPF have some advantage on the patient comfort from first postoperative day to third postoperative day.

• JSTS:Journal of Semiconductor Technology and Science
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• v.2 no.3
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• pp.185-196
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• 2002

MRAM(magnetic random access memory) is a promising candidate for a universal memory with non-volatile, fast operation speed and low power consumption. The simplest architecture of MRAM cell is a combination of MTJ(magnetic tunnel junction) as a data storage part and MOS transistor as a data selection part. This article will review the general development status of MRAM and discuss the issues. The key issues of MRAM technology as a future memory candidate are resistance control and low current operation for small enough device size. Switching issues are controllable with a choice of appropriate shape and fine patterning process. The control of fabrication is rather important to realize an actual memory device for MRAM technology.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.sup1
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• pp.172-176
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• 2008

FDG PET has been used as a diagnostic tool for localization of seizure focus for last 2-3 decades. In this article, the clinical usefulness of FDG PET in the management of patients with epilepsy has been reviewed, which provided the evidences to justify the medicare reimbursement for FDG PET in management of patients with epilepsy. Literature review demonstrated that FDG PET provides an important information in localization of seizure focus and determination whether a patients is a surgical candidate or not. FDG PET has been reported to have high diagnostic performance in localization of seizure focus in neocortical epilepsy as well as temporal lobe epilepsy regardless of the presence of structural lesion on MRI. Particularly, FDG PET can provide the additional information when the results from standard diagnositic modality such as interictal or video-monitored EEG, and MRI are inconclusive or discordant, and make to avoid invasive study. Furthermore, the presence of hypometabolism and extent of metabolic extent has been reported as an important predictor for seizure free outcome. However, studies suggested that more accurate localization and better surgical outcome could be expected with multimodal approach by combination of EEG, MRI, and functional studies using FDG PET or perfusion SPECT rather than using a single diagnostic modality in management of patients with epilepsy. Complementary use of FDG PET in management of epilepsy is worth for good surgical outcome in epilepsy patients.

• Geomechanics and Engineering
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• v.3 no.3
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• pp.207-218
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• 2011

This article describes laboratory research done on strength evaluations for stabilized samples made of tropical fibrous peat. The stabilizing agents used were ordinary Portland cement (OPC) as binding agent and blast furnace slag (BFS) as additive. Stabilized samples were tested for their strength through unconfined compressive strength (UCS) and California bearing ratio (CBR). Different dosage rates of OPC and BFS were used in trial and error experiments for the most effective combination for stabilized peat samples that were at their natural moisture content. Stabilized trial samples were air cured for 90 days. After detecting the most effective dosage rate in the trial samples, their values were used to prepare CBR samples at their optimum moisture content (OMC). CBR samples were then air cured from 1 to 90 days and tested under un-soaked and soaked conditions. The most effective dosage rate for the stabilized peat samples was found to be close to when 75% for OPC and 25% of BFS per total weight of OPC, and BFS. As an example, if 11.25% OPC, and 3.75% BFS are mixed with peat and compacted at their OMC and air cured for 90 days, stabilized peat will have an increase in CBR of 0.8% to 45 % for un-soaked and 20% for soaked conditions.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.4
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• pp.1081-1091
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• 2012

Myelodysplastic syndromes (MDS) represent a heterogeneous group of clonal hematologic neoplasms characterized by morphologic dysplasia, aberrant hematopoiesis and peripheral blood refractory cytopenias. MDS is recognized to be associated with an increased risk of symptomatic anemia, infectious complications and bleeding diathesis, as well as a risk of progression to acute myeloid leukemia, particularly in patients with a high IPSS score. The advent of use of hematopoietic growth factors such as granulocyte colony-stimulating factor (G-CSF) and recombinant erythropoietin (EPO) has improved symptoms in MDS patients in addition to some data that suggest there might be an improvement in survival. G-CSF is an effective therapeutic option in MDS patients, and it should be considered for the management of refractory symptomatic cytopenias. G-CSF and EPO in combination can improve outcomes in appropriate MDS patients such as those with lower-risk MDS and refractory anemia with ring sideroblasts (RARS). This article reviews use of growth factors for lower-risk MDS patients, and examines the data for G-CSF, EPO and thrombopietic growth factors (TPO) that are available or being developed as therapeutic modalities for this challenging disease.