• Journal of the Institute of Electronics Engineers of Korea SP
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• v.46 no.6
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• pp.112-122
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• 2009

In this paper, we present a novel space-frequency adaptive image restoration approach using vaguelette-wavelet decomposition (VWD). The proposed algorithm classifies a degraded image into flat and edge regions by using spatial information of the wavelet coefficient. For reducing the noise we perform an adaptive wavelet shrinkage process. At edge region candidates, we adopt entropy approach for estimating the noise and remove it by using relative between sub-bands. After shrinking wavelet coefficients process, we restore the degraded image using the VWD. The proposed algorithm can reduce the noise without affecting the sharpness details. Based on the experimental results, the proposed algorithm efficiently proved to be able to restore the degraded image while preserving details.

• Smart Structures and Systems
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• v.22 no.4
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• pp.481-493
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• 2018

Ultrasonic guided waves have attracted increasing attention for non-destructive testing (NDT) and structural health monitoring (SHM) of bridge cables. They offer advantages like single measurement, wide coverage of acoustical field, and long-range propagation capability. To design defect detection systems, it is essential to understand how guided waves propagate in cables and how to select the optimal excitation frequency and mode. However, certain cable characteristics such as multiple wires, anchorage, and polyethylene (PE) sheath increase the complexity in analyzing the guided wave propagation. In this study, guided wave modes for multi-wire bridge cables are identified by using a semi-analytical finite element (SAFE) technique to obtain relevant dispersion curves. Numerical results indicated that the number of guided wave modes increases, the length of the flat region with a low frequency of L(0,1) mode becomes shorter, and the cutoff frequency for high order longitudinal wave modes becomes lower, as the number of steel wires in a cable increases. These findings were used in design of transducers for defect detection and selection of the optimal wave mode and frequency for subsequent experiments. A magnetostrictive transducer system was used to excite and detect the guided waves. The applicability of the proposed approach for detecting and locating wire breakages was demonstrated for a cable with 37 wires. The present ultrasonic guided wave method has been found to be very responsive to the number of brokenwires and is thus capable of detecting defects with varying sizes.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.426-428
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• 2003

Optical and microwave remote sensing data have been widely used in land cover and land use classification. Thanks to the spectral absorption characteristics of ground object in visible and near infrared region, optical data enables to extract different land cover types according to their material composition like water body, vegetation cover or bare land. On the other hand, microwave sensor receives backscatter radiance which contains information on surface roughness, object density and their 3-D structure that are very important complementary information to interpret land use and land cover. Separate use of these data have brought many successful results in practice. However, the accuracy of the land use / land cover established by this methodology still has some problems. One of the way to improve accuracy of the land use / land cover classification is just combination of both optical and microwave data in analysis. In this paper for the research, the author used LANDSAT TM scene 127/45 acquired on October 21, 1992, JERS-1 SAR scene 119/265 acquired on October 27, 1992 and aerial photographs taken on October 21, 1992. The study area has been selected in Hanoi City and surrounding area, Vietnam. This is a flat agricultural area with various land use types as water rice, secondary crops like maize, cassava, vegetables cultivation as cucumber, tomato etc. mixed with human settlement and some manufacture facilities as brick and ceramic factories. The use of only optical or microwave data could result in misclassification among some land use features as settlement and vegetables cultivation using frame stages. By combination of multitemporal JERS-1 SAR and TM data these errors have been eliminated so that accuracy of the final land use / land cover map has been improved. The paper describes a methodology for data combination and presents results achieved by the proposed approach.

• Journal of the Korean Magnetics Society
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• v.16 no.5
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• pp.229-233
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• 2006

We investigated the magnetic properties of Fe nanostripes by using the all electron full-potenial linearized augmented plane-wave (FLAPW) energy band method within the generalized gradient approximation (GGA). The magnetic moments of the Fe atoms in the edge Fe chains of the stripes composed of three, five, and seven chains have saturated values of 2.97 or 2.98 ${\mu}_B$, and the values of the center chains are 2.82 ${\mu}_B$ which is similar to that of 2D square lattice. The charge and spin density contour plots showed that the flat distribution in the edge region of the stripes, and it is due to the spilled out p-electrons from the atoms in the edge line. The calculated density of states for the edge atoms in the stripes with seven Fe chains showed that the narrowed width compared to that of center atoms due to the band narrowing effect at the edge.

• The Research Journal of the Costume Culture
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• v.29 no.6
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• pp.779-794
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• 2021

In this study, the sales status of female ball-jointed dolls and their parts were investi- gated and analyzed. Baseline data from 194 products and 54 brands on domestic and international Internet sites was gathered for the manufacture of ball-jointed dolls and the development of prototype costumes for them. The results are as follows. First, the sizes used for ball-jointed dolls are SD, USD, MSD, 13SD, and 70SD together with height. This study analyzed 39 sizes (15~70cm) by classifying them into numbered groups: 1 (15~22cm), 2 (23~33cm), 3 (35~51cm), 4 (53~62cm), and 5 (63~70cm). The price varied depending on the size; for example, 50cm dolls were approximately 45,000 won, while limited editions were sold at high prices, regardless of their size. They were classified into designs according to their body proportions and facial features as follows: 7- or 8-head-figure, 5-head figure, and 3-head figure, and were presented proportionally as images of women, adolescents, and infants. Second, the head was incised so that the top could be removed horizontally or the facial region vertically, allowing attachment of the eyeballs (which were either glass, resin, or acrylic) to the inside. More than 30 different colors were sold. Various wig styles were provided, including cut, short hair, and perm. These were made from human hair, heat-resistant fiber, and artificial hair. For the hands, there was a design expressing human hand gestures. For the feet, heels were in the form of wearing either high-heels or flat soles.

• The Journal of the Acoustical Society of Korea
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• v.42 no.1
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• pp.67-74
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• 2023

The images acquired from the speaker's mouth region revealed the unique patterns according to the corresponding voices. By using this principle, the several methods were proposed in which speech signals were recognized or synthesized from the images acquired at the speaker's lower face. In this study, an image-based speech synthesis method was proposed in which the depth images were cooperatively used. Since depth images yielded depth information that cannot be acquired from optical image, it can be used for the purpose of supplementing flat optical images. In this paper, the usefulness of depth images from the perspective of speech synthesis was evaluated. The validation experiment was carried out on 60 Korean isolated words, it was confirmed that the performance in terms of both subjective and objective evaluation was comparable to the optical image-based method. When the two images were used in combination, performance improvements were observed compared with when each image was used alone.

• The korean journal of orthodontics
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• v.53 no.3
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• pp.185-193
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• 2023

Objective: The growth and development of the mandible strongly depend on modeling changes occurring at its ramus. Here, we investigated covariance patterns between the morphology of the ramus and the rest of the face. Methods: Lateral cephalograms of 159 adults (55 males and 104 females) with no history of orthodontic treatment were collected. Geometric morphometrics with sliding semi-landmarks was used. The covariance between the ramus and face was investigated using a two-block partial least squares analysis (PLS). Sexual dimorphism and allometry were also assessed. Results: Differences in the divergence of the face and anteroposterior relationship of the jaws accounted for 24.1% and 21.6% of shape variation in the sample, respectively. Shape variation was greater in the sagittal plane for males than for females (30.7% vs. 17.4%), whereas variation in the vertical plane was similar for both sexes (23.7% for males and 25.4% for females). Size-related allometric differences between the sexes accounted for the shape variation to a maximum of 6% regarding the face. Regarding the covariation between the shapes of the ramus and the rest of the face, wider and shorter rami were associated with a decreased lower anterior facial height as well as a prognathic mandible and maxilla (PLS 1, 45.5% of the covariance). Additionally, a more posteriorly inclined ramus in the lower region was correlated with a Class II pattern and flat mandibular plane. Conclusions: The width, height, and inclination of the ramus were correlated with facial shape changes in the vertical and sagittal planes.

• Structural Engineering and Mechanics
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• v.87 no.1
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• pp.47-56
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• 2023

Any pre-existed delamination defect present during manufacturing or induce during service loading conditions in the wingskin adherend invariably shows a greater loss of structural integrity of the spar wingskin joint (SWJ). In the present study, inter-laminar delamination propagation at the critical location of the SWJ has been carried out using contact and multi-point constraint finite elements available with commercial FE software (ANSYS APDL). Strain energy release rates (SERR) based on virtual crack closure technique have been computed for evaluation of the opening (Mode-I), sliding (Mode-II) and cross sliding (Mode-III) modes of delamination by sequential release of multi point constraint elements. The variations of different modes of SERR are observed to be significant by considering varied delamination lengths, material properties of adherends and radius of curvature of the SWJ panel. The SERR rates are seen to be much different at the two pre-embedded delamination ends. This shows dissimilar delamination propagation rates. The maximum is seen to occur in the delamination front in the unstiffened region of the wingskin. The curvature geometry and material anisotropy of SWJ adherends significantly influences the SERR values. Increase in the SERR values are observed with decrease in the radius of curvature of wingskin panel, keeping its width unchanged. SWJs made with flat FRP composite adherends have superior resistance to delamination damage propagation than curved composite laminated SWJ panels. SWJ made with Boron/Epoxy (B/E) material shows greater resistance to the delamination propagation.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.26 no.6
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• pp.189-203
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• 2023

This study analyzed potential breeding sites for black-faced spoonbills on 70 non-breeding, uninhabited islands in Incheon, Korea, in order to suggest potential breeding sites for black-faced spoonbills, whose breeding population has recently been increasing. By comparing the environmental characteristics of breeding and non-breeding areas identified through a literature search, we developed a discriminant to identify potential breeding areas for black-faced spoonbills. Among a total of eight environmental variables(Island area, distance from land, distance to mudflat, distance to rice field, distance to sea route, depth of water, mudflat area, rice field area), the variables that influenced the selection of breeding sites for black-faced spoonbills were average water depth, tidal flat area, and paddy field area. As a result of discriminant analysis of breeding islands using these variables, the accuracy was found to be quite high at 80%. As a result of applying the developed discriminant to non-breeding islands located in the Incheon region, a total of 9 islands(Yongrando, Goseokdo, Beolyeom, Joreumseom, Goeriseom, Hambakdo, Moido, Bigajido, Ahyeom) were identified as potential breeding grounds for spoonbills. The research results can be used as basic data for future management of black-faced spoonbill breeding sites and selection of alternative habitats.

• Journal of the Korean Institute of Rural Architecture
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• v.26 no.3
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• pp.29-36
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• 2024

The purpose of this study is to define the characteristics of regional architecture shown in the landscape paintings of Paul Cézanne, who is called the father of modern art, and then to think over the form of regional house in Korea modern architecture. The subject of the study focuses on landscape paintings depicting landscapes among Paul Cézanne's post-impressionist works. The research contents are, first, to understand the landscape structural and cubical characteristics of primary psyche-scene landscapes in his thoughts and insight, and second, to understand the characteristics of regional architecture depicted in his landscape paintings. In this study, characteristics of color in his pictures were excluded, and I attempted to find the origins of pure cube, then tried to pull out the cubical from from Korean regional architecture. The research results are summarized as follows. First, more than 54.7% of Paul Cézanne's paintings are post-impressionism, and the fact that he chose landscapes as the subject of his paintings can be explained to show the value of primary psycho-scene. Second, the building depicted in Paul Cézanne's painting is a pure cube as bastide and mas that are local houses in the Aix-en-Provence region in southern France. Third, Korean cubical flat style of house in the village comes from De Stijl that was provided the concept of Cubism and Mondrian's neo-plasticism.