• The Journal of Korean Academy of Prosthodontics
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• v.43 no.4
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• pp.466-477
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• 2005

Statement of problem : Problem of matching the appearance of porcelain restorations with the patient's natural dentition has always been a concern to dental clinicians. Recently, demands for esthetics, even in restorations requiring strength, has brought a revolution to dentistry and increased use of zirconia. Among the various factors, shade and translucency or the core can significantly affect the overall esthetics of the restoration and should be considered when selecting an all-ceramic system. Purpose : The purpose of this study was to spectrophotometrically evaluate the influence of different zirconia systems and core thickness on the final shade of all-ceramic restorations using the CIEL$^*a^*b^*$ system. Material and Methods: Core specimens (n : 20 per group) of In-Ceram Alumina, In-Ceram Zirconia, Digident CAD/CAM Zirconia, Cercon Zirconia were fabricated 20mm in diameter. 10 specimens of each group were fabricated at core thickness of 0.5mm and 0.7mm. These core specimens were veneered with shade Al & A3 porcelain of the recommended manufacturer. CIEL$^*a^*b^*$ coordinates were recorded for each specimen with a spectrophotometer (Model CM-2600d, Minolta, Japan). Color differences were calculated using the equation ${\Delta}E^*=[({\Delta}L^*)^2+({\Delta}a^*)^2+({\Delta}b^*)^2]^{\frac{1}{2}}$. Results : 1. Specimens of core thickness 0.5mm and 0.7mm did not exhibit clinically perceived color difference. 2. Regarding shade reproducibility, In-Ceram Alumina and In-Ceram Zirconia showed significant difference within each group. 3. Cercon Zirconia group showed the highest $L^*$ value and Digident Zirconia group showed lowest $a^*$ & $b^*$ value. 4. Generally the shade difference between materials was higher in the A3 shade group than in the Al shade group. Conclusion: Within the limitations of this study, there was no color difference after increase in core thickness and every all-ceramic system has color characteristics that clinicians have to consider when selecting materials. Also, manufacturers of different porcelain systems must make every effort to achieve color reproducibility.

• Journal of the Korea Society of Computer and Information
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• v.16 no.11
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• pp.9-15
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• 2011

In this paper, we design and implement of gate management system by face recognition using smart phone. We investigate various algorithms for face recognition on smart phones. First step in any face recognition system is face detection. We investigated algorithms like color segmentation, template matching etc. for face detection, and Eigen & Fisher face for face recognition. The algorithms have been first profiled in MATLAB and then implemented on the Android phone. While implementing the algorithms, we made a tradeoff between accuracy and computational complexity of the algorithm mainly because we are implementing the face recognition system on a smart phone with limited hardware capabilities.

• Journal of Information Technology Application
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• v.3 no.2
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• pp.133-147
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• 2001

This paper proposed a new algorithm for binarization and removal of noises in color images with characters and pictures. Binarization was performed by threshold which had computed with color-relationship relative to the number of pixel in background and character candidates and pre-threshold for dividing of background and character candidates in input images. The pre-threshold has been computed by the histogram of R, G, B In respect of the images, while background and character candidates of input images are divided by the above pre-threshold. As it is possible that threshold can be dynamically decided by the quantity of the noises, and the character images are maintained and the noises are removed to the maximum. And, in this study, we made the noise pattern table as a result of analysis in noise pattern included in the various color images aiming at removal of the noises from the Images. Noises included in the images can figure out Distribution by way of the noise pattern table and pattern matching itself. And then this Distribution classified difficulty of noises included in the images into the three categories. As removal of noises in the images is processed through different procedure according to the its classified difficulties, time required for process was reduced and efficiency of noise removal was improved. As a result of recognition experiments in respect of extracted characters in color images by way of the proposed algorithm, we conformed that the proposed algorithm is useful in a sense that it obtained the recognition rate in general documents without colors and pictures to the same level.

• Journal of the Korean Home Economics Association
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• v.45 no.4
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• pp.43-51
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• 2007

This study analyzed the knit wear trend, which has gained attention as a sensuous and luxury item, through collection magazines, and used the technique of hand-knit to produce and present the knit wear that was designed based on the study results. Accordingly, the purpose of this study is to raise awareness of the expansion of hand knit's new expression techniques and expression areas and to verify its possibility as a higher value-added product. The trends of hand-knit wear resulted from the analysis of collections divided into the following four groups, and the knit designs were also grouped accordingly: First was "The design using object." The trend survey showed the results that the form of drops or flowers was often used as a factor of object. Accordingly, as for the study design, the drop-knitting technique, which is one of the pattern knitting techniques, was used to present a design that employed drops as the object. Second was "The design matched with woven material." It is a way to emphasize aesthetic formativeness and at the same time to activate the area of knit design by matching woven material, which is different from knit in texture, with knit. This study presented a design that tried to combine knit texture and woven material by connecting denim material with various textures and colors. Third was "The design to express see-through." A sense of showing through knit wear was expressed through changes in the type of thread or knitting technique. In this study, the sense of see-through was expressed using piano wires and wool threads and through changes in the thickness of needle. Fourth was "The design to emphasize coloring." It was analyzed that regarding the production of hand knit, the method of coloring expression was to express points, lines and sides or to create harmony by changing the material's color or texture to show particular objects or shapes. In this study, a jacket was designed using the method to express points, lines and sides by changing the material's color.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.11B
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• pp.1339-1345
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• 2011

Red tide is a natural phenomenon that change sea color by harmful algal blooms. There have been many studies on red tide due to increasing of red tide damage. However, to automatically classify the red tide algae is not enough. Recognition of red tide algae is difficult because they do not have matching center features for recognizing algae image object. Previously studies are used a few type of red tide algae for classification. In this paper, we proposed the red tide algae recognition method using PCA and roundness of image objects.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.3
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• pp.330-338
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• 2011

Odometry is the critical factor to estimate the location of the robot. In the mobile robot with wheels, odometry can be performed using the information from the encoder. However, the information of location in the encoder is inaccurate because of the errors caused by the wheel's alignment or slip. In general, visual odometer has been used to compensate for the kinetic errors of robot. In case of using the visual odometry under some robot system, the kinetic analysis is required for compensation of errors, which means that the conventional visual odometry cannot be easily applied to the implementation of the other type of the robot system. In this paper, the novel visual odometry, which employs only the single camera toward the ground, is proposed. The camera is mounted at the center of the bottom of the mobile robot. Feature points of the ground image are extracted by using median filter and color contrast filter. In addition, the linear and angular vectors of the mobile robot are calculated with feature points matching, and the visual odometry is performed by using these linear and angular vectors. The proposed odometry is verified through the experimental results of driving tests using the encoder and the new visual odometry.

• The Research Journal of the Costume Culture
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• v.30 no.1
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• pp.1-15
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• 2022

This study aims to investigate the socio-cultural background of Poulaines, which influenced fashion and contemporary shoe design. Analyzing the characteristics of the Poulaines provided basic data for different shoes. The study method utilized previous studies to explore the concept and characteristics of Poulaines. In the empirical analysis, shoe design data mainly came from collections that illustrate formative elements of contemporary shoe design from the 2010 S/S season to the 2020 S/S season. A total of 709 photo materials were collected and analyzed. The results showed that the morphological characteristics of Poulaines were exaggerated to symbolize classes of the past and sexual expression. The expanding structure was divided into the fore nose, heel, and top-line and featured a design that expressed the formative beauty of Poulaines. Additionally, the decorative desire to represent wealth and class using various materials introduced new designs into contemporary shoe designs while showing extreme decorativeness through over-trimming and color contrast. Furthermore, the heterogeneous characteristics that come from the change and harmony of the shoes' body and heel that deviated from the existing shoe shapes were classified into the dissolution of shapes and mixing and matching. Thus, they broke the monotonous silhouette of shoes and gave variety delicately.

• The Journal of Advanced Prosthodontics
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• v.16 no.1
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• pp.38-47
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• 2024

PURPOSE. This study aims to evaluate the accuracy of different shade selection techniques and determine the matching success of crown restorations fabricated using digital shade selection techniques. MATERIALS AND METHODS. Teeth numbers 11 and 21 were prepared on a typodont model. For the #11 tooth, six different crowns were fabricated with randomly selected colors and set as the target crowns. The following four test groups were established: Group C, where the visual shade selection was performed using the Vita 3D Master Shade Guide and the group served as the control; Group Ph, where the shade selection was performed under the guidance of dental photography; Group S, where the shade selection was performed by measuring the target tooth color using a spectrophotometer; and Group I, where the shade selection was performed by scanning the test specimens and target crowns using an intraoral scanner. Based on the test groups, 24 crowns were fabricated using different shade selection techniques. The ΔE values were calculated according to the CIEDE2000 (2:1:1) formula. The collected data were analyzed by means of a one-way analysis of variance. RESULTS. For the four test groups (Groups C, Ph, S, and I), the following mean ΔE values were obtained: 2.74, 3.62, 2.13, and 3.5, respectively. No significant differences were found among the test groups. CONCLUSION. Although there was no statistically significant difference among the shade selection techniques, Group S had relatively lower ΔE values. Moreover, according to the test results, the spectrophotometer shade selection technique may provide more successful clinical results.

• Journal of Biomedical Engineering Research
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• v.24 no.2
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• pp.61-68
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• 2003

This paper presents a quantitative analysis method for fall in sick times of the cerebral infarction patients using three types of magnetic resonance image, which play an important role in deciding method of medical treatment. For this object, image characteristics obtained by three radiographic methods of MRI and their relation were analyzed by means of object centered hierarchical Planning method. This methode presents an approach to the knowledge based processes for image interpretation and analysis. To compare three type of MRI. a multiple warping algorithm and affine transform method performed for image matching. Then each fall in sick times level of cerebral infarction was quantified and pseudo-color mapping performed by comparing gray level value one another according to Previously obtained hand maid data. The result of this study was compared to a medical doctors decision.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.3
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• pp.91-101
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• 2011

Internet is becoming increasingly popular due to the rapid development of information and communication technology. There has been a convenient social activities such as the mutual exchange of information, e-commerce, internet banking, etc. through cyberspace on a computer. However, by using the convenience of the internet, the personal IDs(identity card, driving license, passport, student ID, etc.) represented by the electronic media are exposed on the internet frequently. Therefore, this study propose a feature extraction method to analyze the characteristics of image files containing personal information and a image retrieval method to find the images using the extracted features. The proposed method selects the feature information from color, texture, and shape of the images, and the images as searched by similarity analysis between feature information. The result which it experiments from the image which it acquires from the web-based image DB and correct image retrieval rate is 89%, the computing time per frame is 0.17 seconds. The proposed method can be efficiently apply a system to search the image files containing personal information and to determine the criteria of exposure of personal information.