• 한국해양학회지
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• v.30 no.6
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• pp.543-549
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• 1995

The inverse method has been used to estimate a surface velocity field from sequential AVHRR/SST data. In the model, equation system was composed of heat equation and horizontal divergence minimization and the velocity field contained in the advective term of the heat equation, which was linearized in grid system, was estimated. A constraint was the minimization of horizontal divergence with weighting factor and introduced to compensate the null space(Menke, 1984) of the velocity solutions for the heat equation. The experiments were carried out to set up the range of weighting factor and the matrix equation was solved by SVD(Singular Value Decomposion). In the experiment, the scales of horizontal temperature gradient and divergence of synthetic velocity field were approximated to those of real field. The neglected diffusive effect and the horizontal variation of heat flux in the heat equation were regarded as random temperature errors. According to the result of experiments, the minimum of relative error was more desirable than the minimum of misfit as the criteria of setting up the weighting factor and the error of estimated velocity field became small when the weighting factor was order of $10^{-1}$

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.12
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• pp.2844-2851
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• 2015

How to recover from the multiple 2D images into 3D object has been widely studied in the field of computer vision. In order to improve the accuracy of the recovered 3D shape, it is more important that noise must be minimized and the number of image frames must be guaranteed. However, potential noise is implied when tracking feature points. And the number of image frames which is consisted of an observation matrix usually decrease because of tracking failure, occlusions, or low image resolution, and so on. Therefore, it is obviously essential that the number of image frames must be secured by recovering the missing feature points under noise. Thus, we propose the analytic approach which can control directly the error distance and orientation of missing feature point by the geometrical properties under noise distribution. The superiority of proposed method is demonstrated through experimental results for synthetic and real object.

• Structural Monitoring and Maintenance
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• v.5 no.1
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• pp.67-78
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• 2018

The stability of cutting slope influences the safety of railway operation, and how to identify the stability of the slope quickly and determine the rational monitoring plan is a pressing problem at present. In this study, the attribute recognition model of risk assessment for high cutting slope stability in the heavy haul railway is established based on attribute mathematics theory, followed by the consequent monitoring scheme design. Firstly, based on comprehensive analysis on the risk factors of heavy haul railway loess slope, collapsibility, tectonic feature, slope shape, rainfall, vegetation conditions, train speed are selected as the indexes of the risk assessment, and the grading criteria of each index is established. Meanwhile, the weights of the assessment indexes are determined by AHP judgment matrix. Secondly, The attribute measurement functions are given to compute attribute measurement of single index and synthetic attribute, and the attribute recognition model was used to assess the risk of a typical heavy haul railway loess slope, Finally, according to the risk assessment results, the monitoring content and method of this loess slope were determined to avoid geological disasters and ensure the security of the railway infrastructure. This attribute identification- risk assessment- monitoring design mode could provide an effective way for the risk assessment and control of heavy haul railway in the loess plateau.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.40 no.5
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• pp.347-356
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• 2003

Camera pose and scene geometry estimation from video sequences is widely used in various areas such as image composition. Structure and motion recovery based on the auto calibration algorithm can insert synthetic 3D objects in real but un modeled scenes and create their views from the camera positions. However, most previous methods require bundle adjustment or non linear minimization process [or more precise results. This paper presents a new auto' calibration algorithm for video sequence based on two steps: the one is key frame selection, and the other removes the key frame with inaccurate camera matrix based on an absolute quadric estimation by LMedS. In the experimental results, we have demonstrated that the proposed method can achieve a precise camera pose estimation and scene geometry recovery without bundle adjustment. In addition, virtual objects have been inserted in the real images by using the camera trajectories.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1995.04a
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• pp.86-86
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• 1995

The analysis of membrane receptors for hormones and neurotransmitters has progressed considerably by pharmacological and biochemical means and more recently by the use of specific anti-receptor antibodies. A 14-mer peptide (from Phe102 to Leu115 of ${\beta}$2-adrenergic receptor) was synthesized and this peptide was coupled to carrier protein Keyhole Limpet Hemocyanin(KLH) by glutaraldehyde method. A 0.5mg of KLH-coupled peptide was emulsified with equal volume of complete Freund's adjuvant and injected via popliteal lymph node to each of the three Newzealnd White rabbits. Booster injections were repeated at 4 weeks interval for three times with incomplete Freund's adjuvants. One week after the final injection, serum was prepared from ear artery. Nonspecific immunoglobulins were removed by passing the serum through KLH-Sepharose 6B affinity matrix and further by incubation with bovine lung aceton powder. The titer of the antibody for synthetic peptide which was determined by enzyme linked immunosorbent assay(ELISA) was about l/l,000. The antibody produced in this study revealed 67kDa protein band in the western blot of partially purified guinea pig lung ${\beta}$-adrenergic receptor preparation. The antibody inhibited ${\beta}$-adrenergic antaginist [3H] Dihydroalprenolol binding to soluble ${\beta}$-adrenergic receptor by 25% while control sera did not show any inhibitory effects, The result of this study suggests that the peptide sequence selected in this study may play some important roles in adrenergic receptor-ligand interaction.

• Geophysics and Geophysical Exploration
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• v.10 no.4
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• pp.259-267
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• 2007

An efficient algorithm for inverting static-shifted magnetotelluric (MT) data has been proposed to produce a three-dimensional (3D) resistivity model. In the Gauss-Newton approach, computational costs associated with construction of a full sensitivity matrix usually make 3D MT inversion impractical. This computational difficulty may be overcome by using approximate sensitivities. We use four kinds of sensitivities in particular orders in the inversion process. These sensitivities are computed 1) analytically for an initial, homogeneous earth, 2) exactly for a current model, 3) approximately by the Broyden method, and 4) approximately using the previous adjoint fields. Inversion experiments with static-shifted synthetic and field MT data indicate that inversion results are highly dependent on characteristics of data and thus applying various combinations of sensitivities is helpful in obtaining a good image of the subsurface structure with reasonable computation time.

• Food Science and Preservation
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• v.10 no.4
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• pp.574-583
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• 2003

There have been a lot of research efforts on development of active food packaging structures and materials in the form of plastic films and containers, along with investigating novel polymers and bioactive compounds for packaging purpose, in order to improve storage stability and safety of foods during distribution and sale. Recently, great interests focus on antimicrobial package films, as an active packaging system, made from synthetic plastic polymer% and natural biopolymers containing various antimicrobial substances for food packaging applications. In this active system, substances are slowly released onto the food surface. However, antimicrobial activity as well as physical properties of the films can be significantly influenced by several factors such as polymer matrix, antimicrobial compounds, and interactions between polymers and compounds. Thus, this study reviews present status of antimicrobial food packaging films in overall performance aspects including types of polymers and active substances, test for antimicrobial activity, and changes in mechanical and antimicrobial properties by preparation method.

• The Journal of the Acoustical Society of Korea
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• v.38 no.2
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• pp.145-153
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• 2019

Adaptive beamforming methods are known to suppress sidelobes and improve detection performance of weak signal by constructing weight vectors depending on the received signal itself. A standard adaptive beamforming like the MVDR (Minimum Variance Distortionless Response) is very sensitive to mismatches between weight vectors and actual signal steering vectors. Also, a large computational complexity for estimating a stable covariance matrix is required when wideband beamforming for a large-scale array is used. In this paper, we exploit the WBRCB (Wideband Robust Capon Beamforming) method for stable and robust wideband adaptive beamforming of a passive large uniform line array sonar. To improve robustness of adaptive beamforming performance in the presence of mismatches, we extract a optimum mismatch parameter. WBRCB with extracted mismatch parameter shows performance improvement in beamforming using synthetic and experimental passive sonar signals.

• Geophysics and Geophysical Exploration
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• v.16 no.3
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• pp.119-130
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• 2013

We developed a method for inverting magnetic data to recover the 3D susceptibility models. The major difficulty in the inversion of the potential data is the non-uniqueness and the vast computing time. The insufficient number of data compared with that of inversion blocks intensifies the non-uniqueness problem. Furthermore, there is poor depth resolution inherent in magnetic data. To overcome this non-uniqueness problem, we propose a resolution model constraint that imposes large penalty on the model parameter with good resolution; on the other hand, small penalty on the model parameter with poor resolution. Using this model constraint, the model parameter with a poor resolution can be effectively resolved. Moreover, the wavelet transform and parallel solving were introduced to save the computing time. Through the wavelet transform, a large system matrix was transformed to a sparse matrix and solved by a parallel linear equation solver. This procedure is able to enormously save the computing time for the 3D inversion of magnetic data. The developed inversion algorithm is applied to the inversion of the synthetic data for typical models of magnetic anomalies and real airborne data obtained at the Geumsan area of Korea.

• Korean Journal of Remote Sensing
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• v.27 no.4
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• pp.435-444
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• 2011

The land cover map derived from spectral features of high resolution optical images has low spectral resolution and heterogeneity in the same land cover class. For this reason, despite the same land cover class, the land cover can be classified into various land cover classes especially in vegetation area. In order to overcome these problems, detailed vegetation classification is applied to optical satellite image and SAR(Synthetic Aperture Radar) integrated data in vegetation area which is the result of pre-classification from optical image. The pre-classification and vegetation classification were performed with MLC(Maximum Likelihood Classification) method. The hierarchical land cover classification was proposed from fusion of detailed vegetation classes and non-vegetation classes of pre-classification. We can verify the facts that the proposed method has higher accuracy than not only general SAR data and GLCM(Gray Level Co-occurrence Matrix) texture integrated methods but also hierarchical GLCM integrated method. Especially the proposed method has high accuracy with respect to both vegetation and non-vegetation classification.