• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.4
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• pp.368-371
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• 2006

The standard procedure outlined by the United States Environmental Protection Agency (US EPA) in Method 1623 for analyzing Giardia lamblia cysts and Cryptosporidium parvum oocysts in water samples consists of filtration, elution, centrifugal concentration, immunomagnetic separation (IMS), and immunofluorescence assay (IFA) followed by microscopic examination. In this study, the extent of (oo)cyst loss in each step of this procedure was evaluated by comparing recovery yields in segmented analyses: (i) IMS + IFA, (ii) concentration + IMS + IFA, and (iii) filtration/elution + concentration + IMS + IFA. The complete (oo)cyst recovery by the full procedure was $52{\sim}57%$. The (oo) cyst loss in the IMS step was only $0{\sim}6%$, implying that IMS is a fairly reliable method for (oo)cyst purification. Centrifugal concentration of the eluted sample and pellet collection before IMS resulted in a loss of $8{\sim}14%$ of the (oo)cysts. The largest (oo)cyst loss occurred in the elution step, with $68{\sim}71%$ of the total loss. The permeated loss of (oo)cysts was negligible during filtration of the water sample with a $1.0-{\mu}m$ pore polyethersulfone (PES) capsule. These results demonstrated that the largest fraction of (oo)cyst loss in this procedure occurred due to poor elution from the filter matrix. Improvements in the elution methodology are therefore required to enhance the overall recovery yield and the reliability of the detection of these parasitic protozoa.

• Textile Coloration and Finishing
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• v.22 no.2
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• pp.101-109
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• 2010

The objective of this study is to investigate the characteristics of natural indigo dyeing of cotton fabric. Reduction and dyeing were carried out by one-step process using an infrared dyeing machine at the liquor ratio of 1:100, and subsequently oxidation and washing in water were followed. Dye uptake was increased with the increase of indigo concentration. Over the full range of dyeing tests, the dyeing condition was optimized to $40^{\circ}C$ for 40min. For most of dye concentrations, the cotton fabrics showed mainly PB color. Maximum K/S value was shown at 4g/L of sodium hydrosulfite concentration and the color strength increased with the increase of dye concentration. Value(lightness) decreased with the increase of dye uptake irrespective of mercerization or reduction method, while the mercerized cotton showed two times higher dye uptake than the untreated cotton. Whereas hue of the untreated cotton showed large decrease of P character(5.6~3.5 PB) with the increase of dye uptake, that of the mercerized cotton increased P character(4.7~5.5 PB). Irrespective of mercerization, value and chroma decreased with the increased of dye uptake. In addition, the untreated showed lower chroma than the mercerized cotton. In the case of traditional reduction, hue of the untreated cotton was changed very little with the increase of dye uptake. For hydrosulfite reduction, P character decreased with the increase of dye uptake. The difference of hue value was small with the change of reduction method(hydrosulfite reduction or traditional fermentation). Color character was not influenced by the changed maximum absorption wavelength. Washing fastness showed 4~4/5 shade change rating without any staining. And dry rubbing fastness was good at low color strength. The bacterial reduction ratios of dyed cotton fabric were also increased.

• Journal of the Society of Naval Architects of Korea
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• v.54 no.1
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• pp.18-25
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• 2017

This study deals with numerically comparing performance according to rudder shape called 'Twisted rudder and Wavy twisted rudder'. In comparison with conventional rudder, rudder with wavy shape has showed a better performance at high angles of attack($30^{\circ}{\sim}40^{\circ}$) due to delaying stall. But most of study concerned with wavy shape had been performed in uniform flow condition. In order to identify the characteristics behind a rotating propeller, the present study numerically carries out an analysis of resistance and self-propulsion for KCS with twisted rudder and wavy twisted rudder. The turbulence closure model, Realizable $k-{\epsilon}$, is employed to simulate three-dimensional unsteady incompressible viscous turbulent and separation flow around the rudder. The simulation of self-propulsion analysis is performed in two step, because of finding optimization case of wavy shape. The first step presents there are little difference between twisted rudder and case of H_0.65 wavy twisted rudder in delivered power. So two kind of rudders are employed from first step to compare lift-to-drag ratio and torque at high angles of attack. Consequently, the wavy twisted rudder is presented as a possible way of delaying stall, allowing a rudder to have a better performance containing superior lift-to-drag ratio and torque than twisted rudder at high angles of attack. Also, as we indicate the flow visualization, check the quantity of separation flow around the rudder.

• International Journal of Fluid Machinery and Systems
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• v.2 no.4
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• pp.392-399
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• 2009

The paper concerns the description of the step by step development process of the new fixed blade runner called "Mixer" suitable for the uprating of the Francis turbines units installed at the older low head hydropower plants. In the paper the details of hydraulic and mechanical design are presented. Since the rotational speed of the new runner is significantly higher then the rotational speed of the original Francis one, the direct coupling of the turbine to the generator can be applied. The maximum efficiency at prescribed operational point was reached by the geometry optimization of two most important components. In the first step the optimization of the draft tube geometry was carried out. The condition for the draft tube geometry optimization was to design the new geometry of the draft tube within the original bad draft tube shape without any extensive civil works. The runner blade geometry optimization was carried out on the runner coupled with the draft tube domain. The blade geometry of the runner was optimized using automatic direct search optimization procedure. The method used for the objective function minimum search is a kind of the Nelder-Mead simplex method. The objective function concerns efficiency, required net head and cavitation features. After successful hydraulic design the modal and stress analysis was carried out on the prototype scale runner. The static pressure distribution from flow simulation was used as a load condition. The modal analysis in air and in water was carried out and the results were compared. The final runner was manufactured in model scale and it is going to be tested in hydraulic laboratory. Since the turbine with the fixed blade runner does not allow double regulation like in case of full Kaplan turbine, it can be profitably used mainly at power plants with smaller changes of operational conditions or in case with more units installed. The advantages are simple manufacturing, installation and therefore lower expenses and short delivery time for turbine uprating.

• Journal of Korean Society for Geospatial Information Science
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• v.22 no.2
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• pp.17-24
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• 2014

This paper proposes an automatic extraction method of control point based on Geospatial Web Service. The proposed method consists of 3 steps. 1) The first step is to acquires reference data using the Geospatial Web Service. 2) The second step is to finds candidate control points in reference data and the target image by SURF algorithm. 3) By using RANSAC algorithm, the final step is to filters the correct matching points of candidate control points as final control points. By using the Geospatial Web Service, the proposed method increases operation convenience, and has the more extensible because of following the OGC Standard. The proposed method has been tested for SPOT-1, SPOT-5, IKONOS satellite images and has been used military standard data as reference data. The proposed method yielded a uniform accuracy under RMSE 5 pixel. The experimental results proved the capabilities of continuous improvement in accuracy depending on the resolution of target image, and showed the full potential of the proposed method for military purpose.

• Proceedings of the IEEK Conference
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• 2000.07b
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• pp.885-888
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• 2000

Among the previous searching methods, there are the typical methods such as full search and three-step search, etc. Block motion estimation using exhaustive search is too computationally intensive. To apply in practice, recently proposed fast algorithms have been focused on reducing the computational complexity by limiting the number of searching points. According to the reduction of searching points, the quality performance is aggravated in those algorithms. In this paper, We present a fast and efficient search algorithm for block motion estimation that produces better quality performance and less computational time compared with a three-step search (TSS). Previously the proposed Two Step Search Algorithm (TWSS) by Fang-Hsuan Cheng and San-Nan sun is based on the ideas of dithering pattern for pixel decimation using a part of a block pixels for BMA (Block Matching Algorithm) and multi-candidate to compensate quality performance with several locations. This method has good quality performance at slow moving images, but has bad quality performance at fast moving images. To resolve this problem, the proposed algorithm in this paper considers spatial and temporal correlation using neighbor and previous blocks to improve quality performance. This performance uses neighbor motion vectors and previous motion vectors in addition, thus it needs more searching points. To compensate this weakness, the proposed algorithm uses statistical character of dithering matrix. The proposed algorithm is superior to TWSS in quality performance and has similar computational complexity

• The KIPS Transactions:PartA
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• v.13A no.2 s.99
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• pp.177-184
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• 2006

Since well-known explicit methods for cloth simulation were regarded unstable for large time steps or stiff springs, implicit methods have been proposed to achieve the stability. Large time step makes the simulation fast, and large stiffness enables a less elastic cloth property. Also, there have been efforts to devise so-called semi-implicit methods to achieve the stability and the speed together. In this paper we improve Kang's method (Kang and Cho 2002), and thus devise a scalable method for cloth simulation that varies from an almost explicit to a full implicit method. It is almost as fast as explicit methods and, more importantly, almost as stable as implicit methods allowing large time steps and stiff springs. Furthermore, it has a less artificial damping than the previously proposed semi-implicit methods.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.797-798
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• 2005

We report a novel structure for a full-color AMOLED (Active Matrix Organic Light Emitting Diode) eliminating the patterning process of a blue emitting layer. The patterning of the three primary colors, RGB, is a key technology in the OLED fabrication process. Conventional full color AMOLED containing RGB layers includes the three opportunities of the defects to make an accurate position and fine resolution using various technologies such as fine metal mask, ink-jet printing and laser-induced transfer system. We can skip the blue patterning step by simply stacking the blue layer as a common layer to the whole active area after pixelizing two primary colors, RG, in the conventional small molecular OLED structure. The red and green pixel showed equivalent performances without any contribution of the blue emission.

• Advanced Composite Materials
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• v.17 no.1
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• pp.1-23
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• 2008

Robotized filament winding technology involves a robot that winds a roving impregnated by resin on a die along the directions of stresses to which the work-piece is submitted in applications. The robot moves a deposition head along a winding trajectory in order to deposit roving. The trajectory planning is a very critical aspect of robotized filament winding technology, since it is responsible for both the tension constancy and the winding time. The present work shows two original rules to plan the winding trajectory of structural parts, whose shape is obtained by sweeping a full section around a 3D curve that must be closed and not crossing in order to assure a continuous winding. The first rule plans the winding trajectory by approximating the part 3D shape with straight lines; it is called the discretized rule. The second rule defines the winding trajectory simply by offsetting a 3D curve that reproduces the part 3D shape, of a defined distance; it is called the offset rule. The two rules have been compared in terms of roving tension and winding time. The present work shows how the offset rule enables achievement of both the required aims: to manufacture parts of high structural performances by keeping the tension on the roving near to the nominal value and to markedly decrease the winding time. This is the first step towards the optimization of the robotized filament winding technology.

• Journal of the Institute of Convergence Signal Processing
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• v.18 no.2
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• pp.62-67
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• 2017

In this paper, we propose a fast motion estimation algorithm which is important in performance of video encoding. Even though so many fast algorithms for motion estimation have been published due to tremendous computational amount of full search algorithm, efforts for reducing computations of motion estimation still remain. In the paper, we propose an algorithm that reduces unnecessary computations only, while keeping prediction quality the same as that of the full search. The proposed algorithm does not calculate block matching error for each candidate directly to find motion vectors but divides the calculation procedure into several steps and calculates partial sum of block errors for candidates with high priority. By doing that, we can find the minimum error point early and get the enhancement of calculation speed by reducing unnecessary computations. The proposed algorithm uses smaller computations than conventional fast search algorithms with the same prediction quality as the full search algorithm.