• Journal of the Society of Naval Architects of Korea
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• v.30 no.3
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• pp.116-126
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• 1993

The finite element method(FEM) has been commonly used for structural dynamic analysis. However, the direct global application of FEM to large complex structures such as ships and offshore structures requires considerable computational efforts, and remarkably more in structural dynamic optimization problems. Adoption of the component-mode synthesis method is an efficient means to overcome the above difficulty. Among three classes of the component-mode synthesis method, the free-interface mode method is recognized to have the advantages of better computational efficiency and easier implementation of substructures' experimental results, but the disadvantage of lower accuracy in analytical results. In this paper, an advanced method to improve the accuracy in the application of the free-interface mode method for the vibration analysis of large complex structures is presented. In order to compensate the truncation effect of the higher modes of substructures in the synthesis process, both residual inertia and stiffness effects are taken into account and a frequency shifting technique is introduced in the formulation of the residual compliance of substructures. The introduction of the frequency shrift ins not only excludes cumbersome manipulation of singular matrices for semi-definite substructural systems but gives more accurate results around the specified shifting frequency. Numerical examples of typical structural models including a ship-like two dimensional finite element model show that the analysis results based on the presented method are well competitive in accuracy with those obtained by the direst global FEM analysis for the frequencies which are lower than the highest one employed in the synthesis with remarkably higher computational efficiency and that the presented method is more efficient and accurate than the fixed-interface mode method.

• Korean Journal of Medicinal Crop Science
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• v.25 no.2
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• pp.108-114
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• 2017

Background: The study was conducted to investigate the distributions of faecal bacteria in commercial oriental medicine herb products. Methods and Results: A survey was conducted on the microbial contamination levels and antimicrobial specificity of Bacillus cereus and other microbes using 106 oriental medicine herb products on sale in Seoul. Pouring and isolation methods such as standard plate counts were used to identify the bacteria. The isolated bacterias included coliforms, Bacillus spp., Enterococcus spp., Staphylococcus spp., Listeria spp.were identified by using gram staining and an API (analytical profile index) kit. Antimicrobial drugs discs were determined by CLSI (clinical and laboratory standards institute). Conclusions: The bacterial isolates present in the herbal medicines included 98 coliforms, 45 Bacillus spp., 29 Enterococcus spp., and 2 Listeria spp. Among these, there were nine Bacillus cereus strains, one Enterococcus faecium strain, and one Enterococcus faecalis strain present. The 9 Bacillus cereus strains were tested for susceptibility to 36 types of antibiotics products by the disc diffusion method. The strains showed resistance to 13 of these antibiotic products and semi-resistance to 5 antibiotic products. On the basis of these results, any oriental medicine herb product can be assumed to be contain resistant or semi-resistant bacterial strains. Therefore, we suggest prescribing guidelines and special management for the use of antibiotics in farms producing oriental medicine herb products.

• The Korean Journal of Applied Statistics
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• v.29 no.6
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• pp.1007-1023
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• 2016

This paper explores the conditions and potential of newly designed and tried methodology of big data analysis that apply to Korean history subject matter. In order to advance them, we need to pay more attention to quantitative analysis methodologies over pre-existing qualitative analysis. To obtain our new challenge, I propose 'digital history' methods along with associated disciplines such as linguistics and computer science, data science and statistics, and visualization techniques. As one example, I apply interdisciplinary convergence approaches to the principle and mechanism of elite reproduction during the Korean medieval age. I propose how to compensate for a lack of historical material by applying a semi-supervised learning method, how to create a database that utilizes text-mining techniques, how to analyze quantitative data with statistical methods, and how to indicate analytical outcomes with intuitive visualization.

• Earthquakes and Structures
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• v.10 no.5
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• pp.1143-1179
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• 2016

Offshore wind turbines are considered as a fundamental part to develop substantial, alternative energy sources. In this highly flexible structures, monopiles are usually used as support foundations. Since the monopiles are large diameter (3.5 to 7 m) deep foundations, they result in extremely stiff short monopiles where the slenderness (length to diameter) may range between 5 and 10. Consequently, their elastic deformation patterns under lateral loading differ from those of small diameter monopiles usually employed for supporting structures in offshore oil and gas industry. For this reason, design recommendations (API and DNV) are not appropriate for designing foundations for offshore wind turbine structures as they have been established on the basis of full-scale load tests on long, slender and flexible piles. Furthermore, as these facilities are very sensitive to rotations and dynamic changes in the soil-pile system, the accurate prediction of monopile head displacement and rotation constitutes a design criterion of paramount importance. In this paper, the Fourier Series Aided Finite Element Method (FSAFEM) is employed for the determination of static impedance functions of monopiles for OWT subjected to horizontal force and/or to an overturning moment, where a non-homogeneous soil profile has been considered. On the basis of an extensive parametric study, and in order to address the problem of head stiffness of short monopiles, approximate analytical formulae are obtained for lateral stiffness $K_L$, rotational stiffness $K_R$ and cross coupling stiffness $K_{LR}$ for both rough and smooth interfaces. Theses expressions which depend only on the values of the monopile slenderness $L/D_p$ rather than the relative soil/monopile rigidity $E_p/E_s$ usually found in the offshore platforms designing codes (DNV code for example) have been incorporated in the expressions of the OWT natural frequency of four wind farm sites. Excellent agreement has been found between the computed and the measured natural frequencies.

• Analytical Science and Technology
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• v.25 no.1
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• pp.33-38
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• 2012

Despite the importance of chloride binding, it is very difficult to measure the binding capacity, in particular, for the concrete body in an existing structure: in fact, the measurement procedure for chloride binding is much influenced by the environmental condition such as temperature, fineness of sample and pore water extraction techniques. The present study concerns the quantification of the binding capacity of chloride ions in concrete using the X-ray diffraction (XRD) technique. Once the binding isotherm of chlorides was determined by the Langmuir isotherm, as a function of the W/C, curing age and binder type, the generation of bound chlorides (i.e. Friedel's salt) was simultaneously ensured by the XRD technique. The amount of bound chloride was then determined by analyzing the peak intensity for the bound chlorides in the XRD curve. It was found that an increase in the curing age and a decrease in the W/C resulted in an increase in the binding capacity.

• Journal of the Korean Association of Geographic Information Studies
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• v.18 no.1
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• pp.48-63
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• 2015

In this study, we introduce various hyperspectral data processing techniques for the monitoring of shallow and coastal waters to enlarge the application range and to improve the accuracy of the end results in Korea. Unlike land, more accurate atmospheric correction is needed in coastal region showing relatively low reflectance in visible wavelengths. Sun-glint which occurs due to a geometry of sun-sea surface-sensor is another issue for the data processing in the ocean application of hyperspectal imagery. After the preprocessing of the hyperspectral data, a semi-analytical algorithm based on a radiative transfer model and a spectral library can be used for bathymetry mapping in coastal area, type classification and status monitoring of benthos or substrate classification. In general, semi-analytical algorithms using spectral information obtained from hyperspectral imagey shows higher accuracy than an empirical method using multispectral data. The water depth and quality are constraint factors in the ocean application of optical data. Although a radiative transfer model suggests the theoretical limit of about 25m in depth for bathymetry and bottom classification, hyperspectral data have been used practically at depths of up to 10 m in shallow and coastal waters. It means we have to focus on the maximum depth of water and water quality conditions that affect the coastal applicability of hyperspectral data, and to define the spectral library of coastal waters to classify the types of benthos and substrates.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.3 no.1
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• pp.32-37
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• 2017

Cis-(1S,4S)-4-(3,4-dichlorophenyl)-1,2,3,4-tertrahydro-N-methyl-1-naphthalenamine (sertraline) hydrochloride from among selective serotonin reuptake inhibitors (SSRIs) is a treatment of major depression. For the differential diagnosis by metabolizing serotonin in a patient with neurological disorders, the radiolabeled $^{11}C$-sertraline was developed for non-invasive positron emission tomography in living brain and use the evaluation of new drug for SSRIs. We release the results of a fast and easy radiolabeling method applied a one-step loop method with $[^{11}C]CH_3OTf$ for routine clinical applications of $^{11}C$-sertraline. 1 mg of a precursor for $^{11}C$-sertraline in 0.1 mL DMF and $5{\mu}L$ of 1N NaOH, were injected into the loop of semi-prep high-performance liquid chromatography (HPLC). $[^{11}C]CH_3OTf$ was passed through the loop at room temperature (RT). The $^{11}C$-sertraline was separated by the semi-preparative HPLC. $^{11}C$-sertraline was eluted at 28.0 min was collected and evaluated by analytical HPLC and mass spectrometer. The total radiolabeling efficiency of $^{11}C$-sertraline was $30.7{\pm}8.7%$. The specific activity was $64.8{\pm}51.4GBq/{\mu}mol$. The radiochemical and chemical purities were higher than 99%. The mass spectrum of the product showed m/z peaks at 307.1 (M+1), indicating the mass of sertraline. By the one-step loop method with $[^{11}C]CH_3OTf$, $^{11}C$-sertraline could be quickly and easily prepared for clinical application.

• Structural Engineering and Mechanics
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• v.45 no.5
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• pp.677-691
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• 2013

A semi-analytical finite strip method is developed for analyzing the post-buckling behavior of rectangular composite laminated plates of arbitrary lay-up subjected to progressive end-shortening in their plane and to normal pressure loading. In this method, all the displacements are postulated by the appropriate harmonic shape functions in the longitudinal direction and polynomial interpolation functions in the transverse direction. Thin or thick plates are assumed and correspondingly the Classical Plate Theory (CPT) or Higher Order Plate Theory (HOPT) is applied. The in-plane transverse deflection is allowed at the loaded ends of the plate, whilst the same deflection at the unloaded edges is either allowed to occur or completely restrained. Geometric non-linearity is introduced in the strain-displacement equations in the manner of the von-Karman assumptions. The formulations of the finite strip methods are based on the concept of the principle of the minimum potential energy. The Newton-Raphson method is used to solve the non-linear equilibrium equations. A number of applications involving isotropic plates, symmetric and unsymmetric cross-ply laminates are described to investigate the through-thickness shearing effects as well as the effect of pressure loading, end-shortening and boundary conditions. The study of the results has revealed that the response of the composite laminated plates is particularly influenced by the application of the Higher Order Plate Theory (HOPT) and normal pressure loading. In the relatively thick plates, the HOPT results have more accuracy than CPT.

• Journal of Korea Spatial Information System Society
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• v.11 no.2
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• pp.45-53
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• 2009

The fast progress on multimedia data acquisition technologies has enabled collecting vast amount of videos in real time. Although the amount of information gathered from these videos could be high in terms of quantity and quality, the use of the collected data is very limited typically by human-centric monitoring systems. In this paper, we propose a framework for analyzing long traffic video using series of content-based analyses tools. Our framework suggests a method to integrate theses analyses tools to extract highly informative features specific to a traffic video analysis. Our analytical framework provides (1) re-sampling tools for efficient and precise analysis, (2) foreground extraction methods for unbiased traffic flow analysis, (3) frame property analyses tools using variety of frame characteristics including brightness, entropy, Harris corners, and variance of traffic flow, and (4) a visualization tool that summarizes the entire video sequence and automatically highlight a collection of frames based on some metrics defined by semi-automated or fully automated techniques. Based on the proposed framework, we developed an automated traffic flow analysis system, and in our experiments, we show results from two example traffic videos taken from different monitoring angles.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.17 no.2
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• pp.105-116
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• 1999

Owing to the rapid development of computer system and the introduction of image processing technique, recent photogrammetric studies have been concentrated on the automation of photogrammetric orientation work that have been carried out by skilled professionals in analog and/or analytical pbotogrammetric field. To automate the whole photogrammetric work, the automation of the orientation processes including interior, relative and absolute orientation should be preceded. This study aims to automate interior orientation and relative orientation process. For this purpose, we applied Hough transform to interior orientation process and object space matching technique to relative orientation process. As the result of this study, we can present a method to automate interior and relative orientation process that has been semi-automatically operated in most commercial digital photogrammetric workstations currently available.