• Journal of the Korean Mathematical Society
• /
• v.58 no.6
• /
• pp.1485-1500
• /
• 2021

A curve is rectifying if it lies on a moving hyperplane orthogonal to its curvature vector. In this work, we extend the main result of [Chen 2017, Tamkang J. Math. 48, 209] to any space dimension: we prove that rectifying curves are geodesics on hypercones. We later use this association to characterize rectifying curves that are also slant helices in three-dimensional space as geodesics of circular cones. In addition, we consider curves that lie on a moving hyperplane normal to (i) one of the normal vector fields of the Frenet frame and to (ii) a rotation minimizing vector field along the curve. The former class is characterized in terms of the constancy of a certain vector field normal to the curve, while the latter contains spherical and plane curves. Finally, we establish a formal mapping between rectifying curves in an (m + 2)-dimensional space and spherical curves in an (m + 1)-dimensional space.

• The Bulletin of The Korean Astronomical Society
• /
• v.43 no.2
• /
• pp.40.2-40.2
• /
• 2018

NGC 5024 and NGC 5053 are among the most metal-poor globular clusters in the Milky Way. Both globular clusters are considered to be accreted from dwarf galaxies (like Sagittarius dwarf galaxy or Magellanic clouds), and common stellar envelope and tidal tails between globular clusters are also detected. We present a search for extra-tidal cluster member candidates around these globular clusters from APOGEE survey data. Using 20 chemical elements (e.g., Fe, C, Mg, Al) and radial velocities, t-distributed stochastic neighbour embedding (t-SNE), which identifies an optimal mapping of a high-dimensional space into fewer dimensions, was explored, and we find that globular cluster stars are well separated from the field stars in 2-dimensional map from t-SNE. We also find that some stars selected in t-SNE map are placed outside of the tidal radius of the clusters. The proper motion of stars outside tidal radius is also comparable to that of globular clusters, which suggest that these stars are tidally decoupled from the globular clusters. We manually measure chemical abundances for the clusters and extra-tidal stars, and discuss the association of extra-tidal stars with the clusters.

• The Journal of Korean Association of Computer Education
• /
• v.8 no.1
• /
• pp.105-115
• /
• 2005

An environment model that is constructed using a single image has the problem of a blurring effect caused by the fixed resolution, and the stretching effect of the 3D model caused when information that does not exist on the image occurs due to the occlusion. This paper introduces the registration and integration method using multiple images to resolve the above problem. This method can represent parallax effect and expand the environment model to represent wide range of environment. The segmentation-based environment modeling method using multiple images can build a detail model with optimal resolution.

• The Journal of the Korea Contents Association
• /
• v.9 no.12
• /
• pp.912-922
• /
• 2009

By 'National GIS Plan', various strategies and programs have been carried out for the professional training in the fields of geospatial information. The e-learning can make it possible to develop and manage the adaptable curriculums, to maximize the effect of the practical exercises, and to establish the cooperative systems with the industries. In this study, curriculums of the geospatial fields were developed and suggested for the cyber universities. These curriculums were divided into three stages, fundamentals, applications, and advances, and into three tracks, system development and construction, mapping and geospatial data construction, and practice and application, based on the current demands in geospatial industries. Owing to be the modularized structure, proposed curriculums would be easily adapted and updated to the change of the new demands.

• Journal of the Korean housing association
• /
• v.27 no.1
• /
• pp.41-50
• /
• 2016

This study aims to draw the factors of support and restriction as children play in the outdoor space through their participation. The 135 students (fifth- and sixth- graders) participated in the research using the mapping method included the daily diagram and the open-ended questionnaire. As the research results, the park, the school yard, the playground and the rest space were emerged as play spaces with high utilization rate. Through the analysis of play spaces based on children's perception, the physical and social-psychological factors are drawn as the factors of support and restriction. Some physical factors such as the location are relevant to social-psychological factors such as the friend and the danger. In conclusion, the physical factors which support or restrict children's activities have to be considered with the socialpsychological factors. And the result from children's experience and perception should be basis of providing appropriate spaces for children who are actual users of play spaces.

• Journal of the Korean association of regional geographers
• /
• v.20 no.1
• /
• pp.128-140
• /
• 2014

This study aims to investigate the characteristics and to classify the foreign volcanic disaster maps. Authors try to extract the components of volcanic disaster maps and apply them to the Mt. Baekdu volcano that receives worldwide attention recently has been on an early stage in Korea. Internationally, volcano ash disaster maps are derived and reviewed through three analytical framework components: Hazard Map, Risk Map, and Damage Map. These derived components of volcano ash disaster mapping systems are: 1) cumulative map of past disaster records, 2) probabilistic risk map, 3) scenario-based map and case-by-case utilization maps (evacuation response type, emergency information type, disaster preparedness education type) based on this components are presented.

• The Journal of the Korea Contents Association
• /
• v.8 no.3
• /
• pp.41-46
• /
• 2008

Many methods have been developed to overcome the PAPR(peak-to-average power ratio) problem. Selective mapping(SLM), partial transmit sequence(PTS), subblock phase weighting(SPW) and gradient descent(GD) are used widely to reduce the PAPR. In this paper, we present an effective PAPR reduction method that decreases the number of calculations through Radix-2 DIF IFFT procedure and GD method that transmits selected data sequence. The data sequence is constructed by choosing elements that satisfy threshold value as one part of the sequence and the rest elements of each sequence are chosen to have the lower papr operating, which yields performance improvement.

• Asian-Australasian Journal of Animal Sciences
• /
• v.25 no.1
• /
• pp.28-32
• /
• 2012

In the present study, we evaluated the informativeness of SNPs genotyped by the Illumina Bovine SNP50K assay in different cattle breeds. To investigate these on a genome-wide scale, we considered 52,678 SNPs spanning the whole autosomal and X chromosomes in cattle. Our study samples consists of six different cattle breeds. Across the breeds approximately 72 and 6% SNPs were found polymorphic and fixed or close to fix in all the breeds, respectively. The variations in the average minor allele frequency (MAF) were significantly different between the breeds studied. The level of average MAF observed in Hanwoo was significantly lower than the other breeds. Hanwoo breed also displayed the lowest number of polymorphic SNPs across all the chromosomes. More importantly, this study indicated that the Bovine SNP50K assay will have reduced power for genome-wide association studies in Hanwoo as compared to other cattle breeds. Overall, the Bovine SNP50K assay described in this study offer a useful genotyping platform for mapping quantitative trait loci (QTLs) in the cattle breeds. The assay data represent a vast and generally untapped resource to assist the investigation of the complex production traits and the development of marker-assisted selection programs.

• Proceedings of the Korea Contents Association Conference
• /
• 2007.11a
• /
• pp.327-330
• /
• 2007

It needs various technology assessment informations to perform reasonable technology valuation. It takes large amount of time and cost to collect technology assessment informations which is same or similar. To provide technology assessment informations efficiently, we develop new system which can batch search and browse all technology assessments gathered from institute of technology valuation, research institute and so on. In this paper, we explain how to use the method such as "metadata integration" and "metadata collection", "mapping for National Science & Technology Standard Classification" as a part of the system.

• The Journal of the Korea Contents Association
• /
• v.15 no.3
• /
• pp.21-31
• /
• 2015

This thesis proposes the emotions acquired after listening to the music as an emotion model composed of 8 types of emotions, based on the emotion model studied previously. The 5 musical factors selected, that affect the emotion, are tempo, dynamics, amplitude change, brightness, and noise. According to the emotion model composed of 8 types of emotions, 160 songs categorized into the 8 types of emotions were selected, and the actual data was extracted and analyzed. Through the analysis of actual data, an emotion equation made of weighted value of 5 factors was derived, and an algorithm that can predict the emotion by mapping on the 2-dimensional emotion coordinate system through the emotion equation was designed. Also, a way of controlling emotion by moving the coordinates on the 2-dimensional emotion coordinate system was suggested.