• Tunnel and Underground Space
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• v.21 no.6
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• pp.427-438
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• 2011

Segment lining is a key permanent lining structure to maintain the shield tunnel stability in shield tunnel operation. Moreover, segment lining generally accounts for the largest proportion in the shield tunnel construction costs. As a result, technical improvements to increase its economic feasibility have been actively carried out. This study aims to propose the development directions of high-performance segments from their recent cutting technologies. In addition, based on over 2,100 world-widely collected segment design data, a series of statistical analyses of segment key design parameters such as thickness, width and the number of divisions as well as segment materials were carried out to approximately estimate them in a design stage.

• Bulletin of the Korean Space Science Society
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• 2006.04a
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• pp.129-132
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• 2006

Animal Tracking System consists of Animal Tracking System Receiver on the Satellite segment, Animal Tracking Terminal and Ground Station for data analysis on the Ground segment. This paper describes operation concept and hardware design for Animal Tracking System which is the payload of HAUSAT-2 being developed by the Space System Research Laboratory (SSRL). Algorithms for determination of animal position and data processing are also referred to.

• Proceedings of the KSPS conference
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• 1996.10a
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• pp.399-403
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• 1996

This paper addresses issues of perceptual constancy in speech perception through the use of a spatial metaphor for speech sound identity as opposed to a more conventional characterisation with multiple interacting acoustic cues. This spatial representation leads to a correlation between phonetic, acoustic and auditory analyses of speech sounds which can serve as the basis for a model of speech perception based on the general auditory characteristics of sounds. The correlations between the phonetic, perceptual and auditory spaces of the set of English voiceless fricatives /f $\theta$ s $\int$ h / are investigated. The results show that the perception of fricative segments may be explained in terms of 2-dimensional auditory space in which each segment occupies a region. The dimensions of the space were found to be the frequency of the main spectral peak and the 'peakiness' of spectra. These results support the view that perception of a segment is based on its occupancy of a multi-dimensional parameter space. In this way, final perceptual decisions on segments can be postponed until higher level constraints can also be met.

• 한국공간정보시스템학회:학술대회논문집
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• 2003.11a
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• pp.159-162
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• 2003

In this paper, to find probable collision positions between moving object and terrain in 3D space efficiently, we use a model, similar to Ray Tracing, which finds the triangles intersected by a directed line segment from a large amount of triangles. We try to reduce dead space as much as possible to find candidate triangles intersected by a directed line segment than previous work's. A new modified octree, LBV-Octree(Least Bounding Voxel Octree), is proposed, and we have a ray tracing with it. In the experiment, ray tracing with LBV-Octree provides $5%{\sim}11%$ better performance than with classical octree.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.2
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• pp.341-351
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• 2015

This study is to select the areas to ensure stream space or to implement flood defence measures according to flood frequencies by classifying the stream segment using river bed slope in Mangyeong river. The analysis result for each stream segment showed that the variation of flood inundation area was small in upper stream catchment. But in the lower stream area, the inundation area became larger greatly according to the increase of flood return period. This study classified the catchment of each steam segment as the region of ensuring stream space (ESS), below 10% residential area ratio, and the region of reinforcing flood defence (RFD), over 10% residential area ratio. The analysis results showed that the lower stream area included more RFD regions than upper stream area, and the upper stream area included more ESS regions than lower stream area. In future study, the regions stream spaces can be ensured will be analyzed considering the past stream morphology and the positions of wetlands.

• The KIPS Transactions:PartB
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• v.12B no.5 s.101
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• pp.527-534
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• 2005

Rotation and scale variations make it difficult to solve the problem of shape description and recognition because these variations change the location of points composing the shape. However, some geometric Invariant points and the relations among them are not changed by these variations. Therefore, if points in image space depicted with the r-y coordinates system can be transformed into a new coordinates system that are invariant to rotation and scale, the problem of shape description and recognition becomes easier. This paper presents a shape description method via transformation from the image space into the invariant feature space having two axes: representing relative distance from a centroid and contour segment curvature(CSC). The relative distance describes how far a point departs from the centroid, and the CSC represents the degree of fluctuation in a contour segment. After transformation, mesh features were used to describe the shape mapped onto the feature space. Experimental results show that the proposed method is robust to rotation and scale variations.

• Journal of KIISE:Software and Applications
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• v.32 no.8
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• pp.742-751
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• 2005

This paper proposes a novel text image watermarking algorithm based on word classification. The words are classified into K classes using simple features. Several adjacent words are grouped into a segment. and the segments are also classified using the word class information. The same amount of information is inserted into each of the segment classes. The signal is encoded by modifying some inter-word spaces statistics of segment classes. Subjective comparisons with conventional word-shift algorithms are presented under several criteria.

• The Journal of the Korean dental association
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• v.16 no.1 s.104
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• pp.37-42
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• 1978

A study on the impacted teeth of the anterior segment was carried out. The data for this study were compiled form 1739 outpatients of the Department of Orthodontics, College of Dentistry, Seoul National University. The following conclusions were obtained; 1. The frequency of the impacted teeth of the anterior segment was 2.8% and the frequency of male was 4.0%, that of female was 2.1%., respectively. 2. The order of occurrence of the impacted teeth in the anterior segment was maxillary canine mesiodens, maxillary central incisor, maxillary lateral incisor, mandibular canine. 3. The etiologic factors of the impaction were the space deficiency for eruption, cleft palate, the prolonged retention of deciduous teeth, dentigerous cyst. 4. The favorable results of treatment and prognosis were obtained from the impacted teeth of the normal shape after surgical exposure and adhered the plastic attachment and inducted them into the dental arch.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.645-647
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• 2003

In this work a new method for on-line scene segmentation is developed. In remote sensing a scene is represented by the pixel-oriented features. It is possible to reduce data redundancy by an unsupervised segment-feature extraction process, where the segment-features, rather than the pixelfeatures, are used for multispectral scene representation. The algorithm partitions the observation space into exhaustive set of disjoint segments. Then, pixels belonging to each segment are characterized by segment features. Illustrative examples are presented, and the performance of features is investigated. Results show an average compression more than 25, the classification performance is improved for all classes, and the CPU time required for classification is reduced by the same factor.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.5
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• pp.839-854
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• 2018

This study was performed to evaluate the performance of GFRP plate reinforced segments for TBM tunnel support. Recently, the SFRC segment has been applied to prevent local damage such as reduction of the amount of reinforcing bars of the segment, crack control and breakage. However, the steel fiber used in the SFRC segment has a problem of durability deterioration due to fiber corrosion. Compared with the RC segment, the maximum flexural load reduction of the SFRC segment hinders the broad application range of the TBM tunnel segment. Therefore, GFRP plate was considered as a stiffener for the maximum load increase of SFRC segment, and structural synthetic fiber without corrosive concern was used as a substitute for steel fiber. The flexural performance of the segment was evaluated by using the type of reinforcing fiber and GFRP plate thickness as the main parameters. As a result, the maximum load and the flexural toughness were increased by 21.78~23.03% and 0.5~7.96%, respectively, as compared with the segments reinforced with reinforcing fiber and GFRP plate of 3 mm thickness.