• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.12
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• pp.43-52
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• 1999

We propose a new method for tuning of center wavelength in photorefractive filter using $LiNbO_3$ crystal doped with 0.015Wt.% Fe. through the filter bandwidth property analysis using the geometrical method, a new wavelength selectivity theory was presented. In this scheme, the tuning of the center wavelength can be achieved by the real time incident angle control of the received heam, which was gotten by the spatial light modulator. So, tuning time depend on the response time of the SLM and results in the high speed turing. Because the use of thermally fixed grating in our filter, it has uniform diffraction property to the all filtering wavelength. Designed tunable filter has 4nm bandwidth and composed of the three channel with 10nm space. From the optical experiment, we get the 4.5nm, 4.25nm, 4nm bandwidth and 1530.5nm, 1540.5nm, 1549.5nm center wavelength respectively.

• Korean Journal of Human Ecology
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• v.13 no.1
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• pp.173-183
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• 2004

The techno fashion presents the new formative beauty of fashion with a stream of light and dynamic phenomenon on human body. Also it opens the futurism arising from the combination of technology with fashion. The purpose of this paper was to investigate the internal trend and external form that techno-fashion aims at, and to analyze the expressive characteristics in design. The results were as follows. ${\cdot}$ The techno fashion created the new formative artifact through the dismantlement and reorganization of form. ${\cdot}$ The techno fashion used the composition of the geometrical abstraction as an expression of beauty symbolizing the modernity. ${\cdot}$ The techno fashion created the diverse colors by using the light along with colors of gold, silver, metal, intense fundamental colors, and artificial rotor. ${\cdot}$ The techno fashion expressed the dynamism, brilliance, youthfulness, futuristic image by using the sense of dazzling brightness by means of metal. ${\cdot}$ The techho fashion along with the development of science and technology made the atmosphere of silhouette of clothes different by expanding the category of materials more widely, together with the possibility of continual emergence of new material. ${\cdot}$ The techno fashion expressed the dynamic movement on clothes and gave the sense of periodical rhythm by the reflective action of light when they were clad. ${\cdot}$ The techno fashion grafted wearable technology into the fashion and made the information instruments recognized as a concept of clothes. ${\cdot}$ The techno fashion pursued the values of not only the beauty of the simple geometrical design, but also the values of functionality and expressed the image of high quality of life through the harmony of technology with human.

• Journal of Korea Multimedia Society
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• v.13 no.5
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• pp.651-662
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• 2010

This paper describes a method to identify objects for autonomous navigation of an outdoor mobile robot. To identify objects, the robot recognizes the object from an image taken by moving robot on outdoor environment. As a beginning, this paper presents the candidates for a segment of region to building of artificial object, sky and trees of natural objects. Then we define their characteristics individually. In the process, we segment the regions of the objects included by preprocessing using multiple features. Multiple features are HSI, line segments, context information, hue co-occurrence matrix, principal components and vanishing point. An analysis of building identifies the geometrical properties of building facet such as wall region, windows and entrance. The building as intersection in vertical and horizontal line segment of vanishing point extracts the mesh. The wall region of building detect by merging the mesh of the neighbor parallelograms that have similar colors. The property estimates the number of story and rooms in the same floors by merging skewed parallelograms of the same color. We accomplish the result of image segmentation using multiple features and the geometrical properties analysis of object through experiments.

• The Journal of Korean Physical Therapy
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• v.22 no.6
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• pp.59-63
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• 2010

Purpose: Driving a car is an essential component of daily life. For safe driving, each driver must perceive sensory information and respond rapidly and accurately. Brake response time (BRT) is a particularly important factor in the total stopping distance of a vehicle, and therefore is an important factor in traffic accident prevention research. The purpose of the current study was (1) to compare accelerometer. BRTs analyzed by three different methods and (2) to investigate possible correlations between accelerometer-BRTs and foot switch-BRTs, which are measured method using a foot switch. Methods: Eighteen healthy subjects participated in this study. BRT was measured with either a tri-axial accelerometer or a footswitch. BRT with a tri-axial accelerometer was analyzed using three methods: maximum acceleration time, geometrical center, and center of maximum and minimum acceleration values. Results: Both foot switch-BRTs and accelerometer-BRTs were delayed. ANOVA for accelerometer BRTs yielded significant main effects for axis and analysis, while the interaction effect between axis and analysis was not significant. Calculating the Pearson correlation between accelerometer-BRT and foot switch-BRT, we found that maximum acceleration time and center of maximum and minimum acceleration values were significantly correlated with foot switch-BRT (p<0.05). The X axis of the geometrical center was significantly correlated with foot switch-BRTs (p<0.05), but Y and Z axes were not (p>0.05). Conclusion: These findings suggest that the maximum acceleration time and the center of maximum and minimum acceleration value are significantly correlated with foot switch-BRTs.

• Journal of Satellite, Information and Communications
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• v.5 no.2
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• pp.45-49
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• 2010

This paper presents the study on multi-beam large aperture antenna systems for a satellite payload. Multi-beam large antenna provides the universal communication and broadcasting services to personal portable terminals. The hybrid antenna composed of a large reflector and a feed array forms multi-beams. The feed cluster consists of a group of feed elements and each element should be optimized for the appropriate amplitude and phase. The optimization progress for amplitude and phase was performed by GO (Geometrical Optics) and PO (Physical Optics) method. The number of feed elements as well as the power level per element were also optimized to meet the required EIRP (Effective Isotropically Radiated Power). In conclusion, 30m-class reflector and twenty five elements for fifteen beams over Korean Peninsula were designed through the optimization process.

• Journal of the Korean Institute of Telematics and Electronics
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• v.12 no.2
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• pp.11-17
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• 1975

The paper examined the character structure as a basic study for the recognition of Korean characters. In view of concave structure, line structure and node relationship of character graph, the algebraic structure of the basic Korean characters is are analized. Also, the degree of complexities in their character structure is discussed and classififed. Futhermore, by describing the fact that some equivalence relations are existed between the 10 vowels of rotational transformation group by Affine transformation of one element into another, it could be pointed out that the geometrical properting in addition to the topological properties are very important for the recognition of Korean characters.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.45 no.5
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• pp.173-179
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• 2008

This paper proposes an efficient 1:N matching scheme for fingerprint identification. Usually, in the minutiae-based matching scheme, fingerprint matching score could be calculated by analyzing geometrical similarity between minutiae from two fingerprints. To calculate the geometrical similarity between them, it is necessary to fingerprint align a fingerprint data with the other one. The final matching score is obtained by bidirectional matching in the common fingerprint matching scheme, because the similarity between two fingerprints varies with the result of alignments. The reliability of matching score by the bidirectional matching is better than by the unidirectional matching, but it takes two times comparing with unidirectional matching. To solve the problem, this paper proposes an efficient 1:N fingerprint matching scheme based on the distribution of bidirectional matching scores for the large fingerprints database. The experimental result shows the usefulness of the proposed scheme.

• Journal of Korea Multimedia Society
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• v.10 no.12
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• pp.1566-1576
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• 2007

Camera pose information from 2D face image is very important for making virtual 3D face model synchronize with the real face. It is also very important for any other uses such as: human computer interface, 3D object estimation, automatic camera control etc. In this paper, we have presented a camera position determination algorithm from a single 2D face image using the relationship between mouth position information and face region boundary information. Our algorithm first corrects the color bias by a lighting compensation algorithm, then we nonlinearly transformed the image into $YC_bC_r$ color space and use the visible chrominance feature of face in this color space to detect human face region. And then for face candidate, use the nearly reversed relationship information between $C_b\;and\;C_r$ cluster of face feature to detect mouth position. And then we use the geometrical relationship between mouth position information and face region boundary information to determine rotation angles in both x-axis and y-axis of camera position and use the relationship between face region size information and Camera-Face distance information to determine the camera-face distance. Experimental results demonstrate the validity of our algorithm and the correct determination rate is accredited for applying it into practice.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1187-1190
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• 2004

This paper presents a traveler guidance system that offers 3D street information such as road types, signal light systems, street trees, buildings, etc. We consider 5x4 road system of Gangnam(in Seoul, Korea) as a test area and reflect the traveler's car-driving situation. A web server is constructed to serve traveler's driving path by switching 3D animation scenes automatically. To do batch processing of geometric data for the 3D graphical streets construction, we have extracted major street information from present GIS database and created new GIS file formats (SMF files), which contain data sessions for links, nodes, and facilities. With these files, we can render 3D navigation scenes. A number of vector calculations were performed for the geometrical consistence and texture-mapping method was used for the realistic scene generation. Finally, we have verified the effectiveness of the service by operating a test scenario. We have checked whether traveler's 2D path and 3D navigation are exactly reported after setting specific departure and destination. This system offers us well awareness of streets and takes useful role of traveler guidance.

• Spatial Information Research
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• v.10 no.3
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• pp.421-438
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• 2002

Abstraction of geographic data within a spatial database context must deal with geometrical simplification, modification or maintenance of the integrity of features, spatial and aspatial data, topology within class, and relationships between classes. This research is to propose a method to abstract a spatial database into a high level database. This study refines operators to carry out the modifications required by the abstraction process in the spatial database. Then, a set of operator sequences (workflows) is suggested to specify operators required to abstract a given feature class and to arrange them in order. Finally, a prototype system is developed, based on rule management with a graphic user interface. When the abstraction process is implemented sequentially we demonstrate that a preferential ordering of operations improves efficiency and reduces loss and distortion in the information.