• Korean Chemical Engineering Research
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• v.52 no.5
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• pp.592-602
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• 2014

In the Integrated Gasification Combined Cycle (IGCC), the stability of the gasifier has strong influences on the rest of the plant as it supplies the feed to the rest of the power generation system. In order to ensure a safe and stable operation of the entrained-flow gasifier and for protection of the gasifier wall from the high internal temperature, the solid slag layer thickness should be regulated tightly but its control is hampered by the lack of on-line measurement for it. In this study, a previously published dynamic simulation model of a Shell-type gasifier is reproduced and two different linear model predictive control strategies are simulated and compared for multivariable control of the entrained-flow gasifier. The first approach is to control a measured secondary variable as a surrogate to the unmeasured slag thickness. The control results of this approach depended strongly on the unmeasured disturbance type. In other words, the slag thickness could not be controlled tightly for a certain type of unmeasured disturbance. The second approach is to estimate the unmeasured slag thickness through the Kalman filter and to use the estimate to predict and control the slag thickness directly. Using the second approach, the slag thickness could be controlled well regardless of the type of unmeasured disturbances.

• Clinical and Experimental Reproductive Medicine
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• v.27 no.4
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• pp.339-344
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• 2000

Objective: To evaluate silane-coated silica particles (Sil-select) as an alternative to polyvinylpyrrolidone-coated particles (Percoll) for gradient separation of spermatozoa, for use in assisted reproduction. Methods: 20 normal semen based on WHO criteria were included in this study. Recovery of motile and morphologically normal spermatozoa after using two-layer Percoll and Sil-select gradient respectively was recorded. Motility, HOST (hypoosmotic swelling test) and the detection of malondialdehyde for LPO (lipid peroxidation) after 24 h of incubation at $37^{\circ}C$ in a 5% $CO_2$ incubator were compared. Results: Percoll (78.5%) and Sil-select (79.1%) showed a significant increase in the motility compared to ejaculate (60.9%) but no difference between Percoll and Sil-select. Normal sperm morphology significantly increased after Percoll (57.6%) and Sil-select (53.7%) compared to ejaculate (35.8%) but no difference between Percoll and Sil-select. No differences in the recovery of motile spermatozoa and motility, HOST and the production of malondialdehyde after 24 h incubation were found when comparing the use of Percoll and Sil-select. Conclusion: Sil-select seems to be an attractive alternative to Percoll for sperm separation in assisted reproduction.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.25 no.2
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• pp.117-131
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• 2007

Representation of building internal space is an active research area as the need for more geometrically accurate and visually realistic increases. 3 dimensional representation is common ground of research for disciplines such as computer graphics, architectural design and engineering and Geographic Information System (GIS). In many cases CAD plans are the starting point of reconstruction of 3D building models. The main objectives of building reconstruction in GIS applications are visualization and spatial analysis. Hence, CAD plans need to be preprocessed and edited to adapt to the data models of GIS SW and then georeferenced to enable spatial analysis. This study automated the preprocessing of CAD data using AutoCAD VBA (Visual Basic Application), and the processed data was topologically restructured for further analysis in GIS environment. Accuracy of georeferencing CAD data was also examined by comparing the results of coordinate transformation by using digital maps and GPS measurements as the sources of ground control points. The reconstructed buildings were then applied to visualization and network modeling.

• Journal of Life Science
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• v.19 no.5
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• pp.671-675
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• 2009

Prostate cancer has been a critical health problem due to an increase of prostate cancer-related deaths worldwide. Also, a frequent treatment option for prostate cancer is androgen ablation, but this treatment has a limited scope, especially for hormone-refractory cancer. There is an urgent need for the identification of alternative therapeutic strategies for prostate cancer. Previously, over one hundred species of dried-plant methanol extracts were tested for inhibitory effects on proliferation. One of them, Piper longum Linn. was selected based on its potent anti-proliferation effect. The dried root of P. longum Linn. was extracted with 100% methanol for 2-3 days and its extract was fractionated using chloroform. The chloroform layer was then subjected to column chromatography on silica gel, reverse phase-18 (RP-18) and Sephadex LH-20, in turn. Finally, the pure compound was obtained and identified as pipernonaline by NMR spectroscopic and physico-chemical analysis. In this study, anti-proliferation and cell cycle arrest effects of pipernonaline on human prostate cancer PC-3 cells were investigated using the MTT and PI staining, respectively. Our findings suggest that pipernonaline represents a dose-dependent growth inhibition pattern on PC-3 cells and, moreover, its growth inhibition is associated with sub-G1 and G0/G1 cell cycle accumulation in PC-3 cells. Also, these results provide an anticancer candidate for human prostate cancer.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.12 no.1
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• pp.41-61
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• 1990

This study was undertaken to investigate the effect of indomethacin on the distribution of Langerhans cells and T-lymphocytes related with immune response of 4-Nitroquinoline-1-oxide induced carcinogenesis at the palate and tongue of albino rat. 54 Sprague-Dawley strain 10 weeks old albino rats, about 150gm weighted, divided into a normal group of 6 rats without treatment, a control group of 12 rats given indomethacin, a carcinogenesis group of 18 whose palatal mucosa were appiled with 4-Nitroquinoline-1-oxide three times a week, and experimental group of 18 rats were treated with indomethacin and whose palatal mucosa were applied 4-Nitroquinoline-1-oxide. All these 54 rats were subjected to be observed as being ATPase stained specimens, specimens for the observation of light and electron microscope, and T-lymphocyte stained specimens. The obtained results were summarized as follows; 1. In carcinogenesis group, proliferation of epithelial layer and rete peg were observed early period of the experiment and showed parakeratosis, individual cell keratinization, acanthosis, and lymphocyte infiltration from 13th week of the experiment on lightmicroscopically, while experimental group showed less reaction than that of carcinagenesis group. 2. The number of Langerhans cells in normal group rarely changed until 21st week of the experiment, while the Langerhans cells increased markedly from 3rd week of the experiment in control group. 3. The number of Langerhans cells were decreased markedly and persistantly until 21st week of the experiment both in carcinogenesis and experimental groups. 4. Appearance of the T-helper cells and T-suppressor cells were minimal and irregullar in number both in normal and control groups. Thus it is assumed that administration of indomethacin and distribution of Langerhans cells showed close relation. 5. In carcinogenesis and experimental groups, the number of the T-helper cells was apparently inereased than that of the T-suppressor cells, but increasing pattern in experimental group was less than in carcinogenesis group. These cells increased most in the 21st week, decreased from the 23rd week and the appearance of these cells were irregular in general throughout the experiment.

• Geophysics and Geophysical Exploration
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• v.13 no.1
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• pp.51-60
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• 2010

To determine subglacial topography and internal features of the Fourcade Glacier on King George Island in Antarctica, helicopter-borne and ground-towed ground-penetrating radar (GPR) data were recorded along four profiles in November 2006. Signature deconvolution, f-k migration velocity analysis, and finite-difference depth migration applied to the mixed-phase, single-channel, ground-towed data, were effective in increasing vertical resolution, obtaining the velocity function, and yielding clear depth images, respectively. For the helicopter-borne GPR, migration velocities were obtained as root-mean-squared velocities in a two-layer model of air and ice. The radar sections show rugged subglacial topography, englacial sliding surfaces, and localised scattering noise. The maximum depth to the basement is over 79m in the subglacial valley adjacent to the south-eastern slope of the divide ridge between Fourcade and Moczydlowski Glaciers. In the ground-towed profile, we interpret a complicated conduit above possible basal water and other isolated cavities, which are a few metres wide. Near the terminus, the GPR profiles image sliding surfaces, fractures, and faults that will contribute to the tidewater calving mechanism forming icebergs in Potter Cove.

• Journal of the Korean GEO-environmental Society
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• v.13 no.12
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• pp.5-16
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• 2012

The second scientific antarctic station of South Korea is under construction at Terra Nova Bay located in eastern Antarctica. Ground condition in the Antarctica is frozen in general, but there are seasonal frozen grounds with active layers sporadically. When the active layer is frozen, frost heaving occurs that might cause the differential movement of frozen ground and the failure of structures. Therefore, it is necessary to determine the frost heaving susceptibility of soils at Terra Nova Bay before starting antarctic station construction. This study presents experimental investigation of the frost heaving susceptibility of soil samples with variation of particle sizes and unfrozen water contents. The soil samples were taken from five different locations at Terra Nova Bay and physical properties, unfrozen water content, and frost heaving tests were performed. For the frost heaving tests, soil specimens were frozen with constant freezing temperatures at the top and with drainage at the bottom in order to stimulate the frost heaving. The frost heaving tests provide volume expansion, volumetric strain, and heaving rate which can be used to analyze the relationship between the frost heaving vs. particle size and the frost heaving vs. unfrozen water content. Experimental results show that the more the fine contents exist in soils, the more frost heaving occurs. In addition, the frost heaving depends on unfrozen water content. Experimental data can be used to evaluate the frost heaving susceptibility of soils at the future construction site in the Antarctica.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.5 no.6
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• pp.72-85
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• 2002

This study was conducted to investigate the germination rates and ground coverage rates of the 16 native wild flower, herbaceous, shrub and woody plants according to temperature and seeding timing for the revegetation and rehabilitation of the roadside slopes. Also, this study was conducted to suggest design criteria to select revegetation plants and to decide proper seed mixture for ecological restoration of the disturbed manmade slopes as a environmentally friendly construction. The results are summarized as follows. 1. Most of the plants germinated after 10~14 days. Woody plants germinated more slowly than wild flowers and herbaceous plants because of the hard seed. 2. Most of the plants showed the highest percentage of the germination rates under $15/25^{\circ}C$ temperature. The next was in order of under the $20/30^{\circ}C$ temperature, normal temperature(October) and $25/35^{\circ}C$ temperature. 3. At the chamber experiment, the Sorbaria sorbifolia var. stellipila showed the highest germination rates. Most of the native wild flowers germinated well and showed high germination rates under the various temperature. 4. As the field germination experiments, the seeding at August shows higher germination rates than that of the seeding at September, but showed lower surviving percentage of the germinated seedlings and lower ground coverage percentage than those of the seeding at September. After one year, Chionanthus retusus, Acer palmatum, Albizzia julibrissin are germinated and showed 10% coverage rates. So, they can be used as revegetation plants for the restoration works. 5. As seed mixture experiment, it was not effective only to increase the proportion of the ratio of the tree seeds, relatively high price, for making woody vegetation. It would be more successful to make vegetation structure by natural competition among wild flowers, shrubs and trees. 6. The excessive dominance of trees in revegetation works may destroy the lower layer of vegetation and it will be undesirable on the species diversity. It is more important to recover the species diversity of the plant community by seed mixture with the considering the germination, the growth characteristics and the correlation effect among revegetation plants. 7. To recover the manmade slopes quickly, increasing the ratio of the wild flower was recommended.

• Journal of Korean Ophthalmic Optics Society
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• v.7 no.2
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• pp.1-11
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• 2002

A mathematical model is proposed to analyze the force; acting on the hard contact lens fitted on the cornea. The model incorporates the nonlinear equations and their numerical solution program, based on the formulations of surface tension force arising from the capillary action in the tear-film layer between the lens and cornea. The model simulates how the adhesion between lens and cornea varies according to the base curves and diameters of the lenses. When the spherical lens is fitted on the spherical cornea it is to rotate downward due to the weight of lens itself until it reaches an equilibrium position along the cornea where the counter(upward) moment caused by net force between the upper and lower portion of the periphery of lens. It is found that both the adhesion and displacement of lens along the cornea, where the gravity of lens balances the capillary-induced upward force, increases rapidly as the base curve of lens increases, i.e., as the lens gets flatter, while the increase in the diameter of lenses has resulted in the less increase in the rotation and adhesion. With the base curve and diameters of lenses being remained constant the increase in surface tension of tear film yields the increase in the adhesion between the cornea and lens while the initial rotation of lens is inversely proportional to the surface tension of the tear film.

• Korean Journal of Remote Sensing
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• v.28 no.5
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• pp.489-499
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• 2012

In this paper, a classifier ensemble framework for remote sensing data classification is presented that combines classification results generated from both different training sets and different classifiers. A core part of the presented framework is to increase a diversity between classification results by using both different training sets and classifiers to improve classification accuracy. First, different training sets that have different sampling densities are generated and used as inputs for supervised classification using different classifiers that show different discrimination capabilities. Then several preliminary classification results are combined via a majority voting scheme to generate a final classification result. A case study of land-cover classification using multi-temporal ENVISAT ASAR data sets is carried out to illustrate the potential of the presented classification framework. In the case study, nine classification results were combined that were generated by using three different training sets and three different classifiers including maximum likelihood classifier, multi-layer perceptron classifier, and support vector machine. The case study results showed that complementary information on the discrimination of land-cover classes of interest would be extracted within the proposed framework and the best classification accuracy was obtained. When comparing different combinations, to combine any classification results where the diversity of the classifiers is not great didn't show an improvement of classification accuracy. Thus, it is recommended to ensure the greater diversity between classifiers in the design of multiple classifier systems.