• The korean journal of orthodontics
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• v.53 no.5
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• pp.317-327
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• 2023

Objective: This study aimed to evaluate the association between low tongue position (LTP) and the volume and dimensions of the nasopharyngeal, retropalatal, retroglossal, and hypopharyngeal segments of the upper airway. Methods: A total of 194 subjects, including 91 males and 103 females were divided into a resting tongue position (RTP) group and a LTP group according to their tongue position. Subjects in the LTP group were divided into four subgroups (Q1, Q2, Q3, and Q4) according to the intraoral space volume. The 3D slicer software was used to measure the volume and minimum and average cross-sectional areas of each group. Airway differences between the RTP and LTP groups were analyzed to explore the association between tongue position and the upper airway. Results: No significant differences were found in the airway dimensions between the RTP and LTP groups. For both retropalatal and retroglossal segments, the volume and average cross-sectional area were significantly greater in the patients with extremely low tongue position. Regression analysis showed that the retroglossal airway dimensions were positively correlated with the intraoral space volume and negatively correlated with A point-nasion-B point and palatal plane to mandibular plane. Males generally had larger retroglossal and hypopharyngeal airways than females. Conclusions: Tongue position did not significantly influence upper airway volume or dimensions, except in the extremely LTP subgroup.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.17 no.5
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• pp.358-366
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• 2024

This paper proposes a method for the real-time camera tracking which detects and employs feature points located on a planar object in 3D space. The proposed approach operates in two stages. First, multiple feature points are detected in the 3D space, and then only those that exist on the planar object are selected. The camera's extrinsic parameters are then estimated using the projective geometry relationship between the feature points of the plane and the camera's image plane. The experiments are conducted in a typical indoor environment with regular lighting, without any special illumination setups. In contrast to conventional approaches, the proposed method can detect new feature points on the planar object in real-time and employ them for the camera tracking. This allows for continuous tracking even when the reference features for the camera pose initialization are not available. The experimental results show an average re-projection error of about 5 to 7 pixels, which is relatively small given the image resolution, and demonstrating that camera tracking is possible even in the absence of reference features within the image.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.4 no.1
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• pp.101-110
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• 2004

The robots that will be needed in the near future are human-friendly robots that are able to coexist with humans and support humans effectively. To realize this, humans and robots need to be in close proximity to each other as much as possible. Moreover, it is necessary for their interactions to occur naturally. It is desirable for a robot to carry out human following, as one of the human-affinitive movements. The human-following robot requires several techniques: the recognition of the moving objects, the feature extraction and visual tracking, and the trajectory generation for following a human stably. In this research, a predictable intelligent space is used in order to achieve these goals. An intelligent space is a 3-D environment in which many sensors and intelligent devices are distributed. Mobile robots exist in this space as physical agents providing humans with services. A mobile robot is controlled to follow a walking human using distributed intelligent sensors as stably and precisely as possible. The moving objects is assumed to be a point-object and projected onto an image plane to form a geometrical constraint equation that provides position data of the object based on the kinematics of the intelligent space. Uncertainties in the position estimation caused by the point-object assumption are compensated using the Kalman filter. To generate the shortest time trajectory to follow the walking human, the linear and angular velocities are estimated and utilized. The computer simulation and experimental results of estimating and following of the walking human with the mobile robot are presented.

• Journal of Astronomy and Space Sciences
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• v.34 no.2
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• pp.161-170
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• 2017

In this study, the characteristics of a horizontal sundial from the Joseon Dynasty were investigated. Korea's Treasure No. 840 (T840) is a Western-style horizontal sundial where hour-lines and solar-term-lines are engraved. The inscription of this sundial indicates that the latitude (altitude of the north celestial pole) is $37^{\circ}$ 39', but the gnomon is lost. In the present study, the latitude of the sundial and the length of the gnomon were estimated based only on the hour-lines and solar-term-lines of the horizontal sundial. When statistically calculated from the convergent point obtained by extending the hour-lines, the latitude of this sundial was $37^{\circ}$ $15^{\prime}{\pm}26^{\prime}$, which showed a 24' difference from the record of the inscription. When it was also assumed that a convergent point is changeable, the estimation of the sundial's latitude was found to be sensitive to the variation of this point. This study found that T840 used a vertical gnomon, that is, perpendicular to the horizontal plane, rather than an inclined triangular gnomon, and a horn-shaped mark like a vertical gnomon is cut on its surface. The length of the gnomon engraved on the artifact was 43.1 mm, and in the present study was statistically calculated as $43.7{\pm}0.7mm$. In addition, the position of the gnomon according to the original inscription and our calculation showed an error of 0.3 mm.

• Journal of the Korea Society of Computer and Information
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• v.17 no.1
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• pp.161-169
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• 2012

In general, Euclidean minimum spanning tree is a tree connecting input nodes with minimum connecting cost. But the tree may not be optimal when applied to real world problems of three dimension. In this paper, three dimension Euclidean minimum spanning tree is proposed, connecting all input nodes of 3-dimensional space with minimum cost. In experiments for 30,000 input nodes with 100% space ratio, the tree produced by the proposed method can reduce 90.0% connection cost tree, compared with the tree by two dimension Prim's minimum spanning tree. In two dimension plane, the proposed tree increases 251.2% connecting cost, which is pointless in 3-dimensional real world. Therefore, the proposed method can work well for many connecting problems in real world space of three dimensions.

• Science of Emotion and Sensibility
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• v.10 no.1
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• pp.37-47
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• 2007

Color planning system can be treated as a decision support system which includes both the recommendation of main color and harmonious colors. In this paper, we propose techniques that are useful to enhance the harmonious color recommendation with the main color selected by user. In order to reflect the knowledge about suggestion of harmonious colors, we use Ostwald color harmony theory, that is very systematical and easy to implement. Actually, Ostwald color space is similar to HMMD color model in MPEG-7. Due to the similarity between two color spaces, Ostwald color space can be represented as a virtual HMMD color space. Accordingly, we propose a technique to align the HMMD color space with Ostwald color space, thereby it is capable of enhancing a performance to search the harmonious colors according to Ostwald harmony theory. For recommendation of delicate and more exquisite harmonious colors in equal hue plane, we made the virtual color space continuous. The system can recommend various harmonious colors according to Ostwald color harmony. He(she) can select harmonious colors among the suggestions from the system.

• Korean Institute of Interior Design Journal
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• v.16 no.5
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• pp.63-70
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• 2007

A relationship between the museum display wall composition and the visual spatial configuration is investigated in this study. From the previous research, existing types are classified in order to define the exhibition space of room to room. Based on the classification, an open room to room of art museum is defined as a room to room of museum, and the plane of museums is investigated. With the museums under this study, the wall of a room to room exhibition space as well as the visual spatial configuration are analyzed depending on the location of an opening, centering on the composition of unit space. In addition, two types of spatial composition are compared depending on the location of the opening. One type of spatial composition is lied on a straight line with visual continuity, and the visual line is found to be simple. Whereas, the other type has an invisible configuration between spaces due to a criss-crossed opening, so the space is perceived to be closed and disconnected. When comparing these two types, the advantage and disadvantage of each space are compared. As a result, a similar type and size of unit space are derived. In addition, the ratio of the opening compared to the total wall was found to be uniform, and a distribution of the opening and walls were found.

• Proceedings of the KSRS Conference
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• 1998.09a
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• pp.319-324
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• 1998

Ocean Scanning Multispectral Imager (OSMI) is a payload on the Korean Multi-purpose SATellite (KOMPSAT) to perform worldwide ocean color monitoring for the study of biological oceanography. The instrument images the ocean surface using a whisk-broom motion with a swath width of 800 km and a ground sample distance (GSD) of < 1 km over the entire field-of-view (FOV). The instrument is designed to have an on-orbit operation duty cycle of 20% over the mission lifetime of 3 years with the functions of programmable gain/offset and on-board image data storage. The instrument also performs sun calibration and dark calibration for on-board instrument calibration. The OSMI instrument is a multi-spectral imager covering the spectral range from 400 nm to 900 nm using a CCD Focal Plane Array (FPA). The ocean colors are monitored using 6 spectral channels that can be selected via ground commands after launch. The instrument performances are fully measured for 8 basic spectral bands centered at 412nm, 443nm, 490nm, 510nm, 555nm, 670nm, 765nm and 865nm during ground characterization of instrument. In addition to the ground calibration, the on-board calibration will also be used for the on-orbit band selection. The on-orbit band selection capability can provide great flexibility in ocean color monitoring.

• Journal of Digital Contents Society
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• v.16 no.6
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• pp.909-916
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• 2015

This paper presents a method to display the 3D vector fields by analyzing phase space. This method is based on the connections between ordinary differential equations and the topology of vector fields. The phase space analysis should be geometric interpolation of an autonomous system of equation in the form of the phase space. Every solution of it system of equations corresponds not to a curve in a space, but the motion of a point along the curve. This analysis is the basis of this paper. This new method is required to decompose the hexahedral cell into five or six tetrahedral cells for 3D vector fields. The critical points can be easily found by solving a simple linear system for each tetrahedron. The tangent curves can be integrated by finding the intersection points of an integral curve traced out by the general solution of each tetrahedron and plane containing a face of the tetrahedron.

• Journal of the Korean housing association
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• v.19 no.6
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• pp.9-20
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• 2008

The residential environment is a place which reflects the gradual evolution of human consciousness because it is a cultural space the term, 'houses' is not relevant in this context as it literally means 'contains'. The long history of human living habits cannot be 'contained' within a space, but can be 'expressed' by a space and by the way the space is used. Furthermore, due to the way it is typically constructed, the basic characteristics of the house usually cannot be rapidly changed to accommodate new habits. However, recent changes that have taken place to the characteristics of the traditional master room suggest that traditional societal values associated with patriarchy have diminished. The current trend where priority is given to children's education also affects such a change. Existing researches related to the master room is confined to the behavioral use of the space and the composition of the physical space, while research on the master room its plane type has not been carried out. Therefore, in this study, apartment model houses are selected, and are classified according to the types of master room. An analysis is then carried out of the master room based on the occupants' requirements in terms of consciousness. Any planning modifications where required are then suggested. This research comprises the followings stages. First, an examination is carried out of existing research on the master room in order to understand its background and spatial components. A definitiones of related terms is also provided. Second, an analysis is carried out of the model houses exhibited at Suwan District, examining the typical standard that has been selected for the master room. Third, an analysis is conducted of the topics and questions to be selected for a questionnaire. Fourth, an analysis is carried out of the consciousness, satisfaction and requirements of the residents, as respondents in the questionnaire, related to the master room. and Research is then conducted of the architectural methods for planning the master room. Finally, future countermeasures for planning the master room are described based on the above analysis and research findings.