• Spatial Information Research
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• v.16 no.2
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• pp.237-247
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• 2008

Statistical analysis of the coordinate information is regarded as one of the major GIS functions. Among them, one of the most fundamental analysis is density analysis of point features. For analyzing the density appropriately, determining the search radius, kernel radius, has critical importance. In this study, using L-index, known as its usefulness for choosing the kernel radius in previous researches, radius for density analysis of various point features are estimated, and the behavior of L-index is studied based on the estimated results. As results, L-index is not suitable to determine the search radius for the point features that are evenly distributed with small clusters, because the pattern of the L-index is depends on the size of the study area. But for the point features with small number of highly clustered areas, L-index is suitable, because the pattern of the L-index is not affected by the size of study area.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.24 no.1
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• pp.81-96
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• 2021

The purpose of this study was conducted in order to provide the necessary basic data, to establish management solutions and to improve biodiversity by calculating similarity index, urbanization index (UI), and disturbed index (DI) to understand current status of naturalized and invasive alien plants in Eulsukdo, Maekdo and Samnak ecological parks in Busan, South Korea. The numbers of naturalized plants identified in these parks were 76 taxa; 20 families, 53 genera, and 76 species. As a result of the similarity index analysis, the most similarity level (83.0%) was obtained at Eulsukdo and Maekdo parks. The numbers of invasive plants identified in the two parks were 11 taxa; Rumex acetosella L., Sicyos angulatus L., Solanum carolinense L., Ambrosia artemisiifolia L., Ambrosia trifida L., Hypochaeris radicata L., Lactuca serriola L., Solidago altissima L., Symphyotrichum pilosum (Willd.) G.L.Nesom, Paspalum distichum L., and Humulus scandens (Lour.) Merr. Overall, UI and DI were 28.6% and 66.7%, respectively, indicating that the ecosystem disruption was serious.

• Journal of KIISE:Databases
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• v.33 no.1
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• pp.12-31
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• 2006

The n-gram inverted index has two major advantages: language-neutral and error-tolerant. Due to these advantages, it has been widely used in information retrieval or in similar sequence matching for DNA and Protein databases. Nevertheless, the n-gram inverted index also has drawbacks: the size tends to be very large, and the performance of queries tends to be bad. In this paper, we propose the two-level n-gram inverted index (simply, the n-gram/2L index) that significantly reduces the size and improves the query performance while preserving the advantages of the n-gram inverted index. The proposed index eliminates the redundancy of the position information that exists in the n-gram inverted index. The proposed index is constructed in two steps: 1) extracting subsequences of length m from documents and 2) extracting n-grams from those subsequences. We formally prove that this two-step construction is identical to the relational normalization process that removes the redundancy caused by a non-trivial multivalued dependency. The n-gram/2L index has excellent properties: 1) it significantly reduces the size and improves the Performance compared with the n-gram inverted index with these improvements becoming more marked as the database size gets larger; 2) the query processing time increases only very slightly as the query length gets longer. Experimental results using databases of 1 GBytes show that the size of the n-gram/2L index is reduced by up to 1.9${\~}$2.7 times and, at the same time, the query performance is improved by up to 13.1 times compared with those of the n-gram inverted index.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.31 no.6_2
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• pp.601-609
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• 2013

Standard lots, which are used to assess values of individual lots in Korea, have been criticized for their improper distribution. However, there has been very little evaluation for the spatial distribution of standard lots, and an evaluation method has never been developed. In order to overcome this situation, we attempt to assess the appropriateness of the spatial distribution of standard lots using the L-index and Monte Carlo simulation. The L-index is a well-known indicator of the complete spatial randomness (CSR) of points in spatial statistics. If the L-index of standard lots is similar to that of individual lots, the former is considered to be randomly distributed according to the latter. By analyzing L-indices of two study areas, Gangnam and Seongdong, we find a statistically significant difference in Gangnam area and a relatively small difference in Seongdong area. We confirm that the spatial distribution of standard lots is not CSR and that the L-index is useful as an evaluation method. These results suggest that the standard lot selection and management guidelines need to be modified to apply the spatial distribution of individual lots to the standard lot selection process.

• The Pure and Applied Mathematics
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• v.25 no.3
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• pp.193-201
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• 2018

In this paper, we discuss central index oriented and slowly changing function based some growth properties of composite entire functions.

• Kyungpook Mathematical Journal
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• v.55 no.3
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• pp.615-624
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• 2015

We present some estimates for the polynomial numerical index of $l_p$ (1 < p < ${\infty}$).

• Journal of the Korean Mathematical Society
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• v.37 no.6
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• pp.901-913
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• 2000

This is a summary of results involving the development of a theory of an index of an isolated critical point for densely defined nonlinear operators of type (S(sub)+)(sub)0,L. This index theory is associated with a degree theory, for such operators, whch has been recently developed by the authors.

• Journal of the Korean Association of Geographic Information Studies
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• v.11 no.1
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• pp.155-166
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• 2008

The quantitative bivariate spatial pattern analysis was applied for the water quality and nutrients data of Masan Bay, and for this analysis Pearson's r as aspatial correlation measurement, Moran's I as spatial association measurement and L index as integration of aspatial and spatial measurement methods were used. To understand the aspatial and spatial characteristics implicated in L index, Pearson's r as well as Moran's I were classified into 3 types respectively, and Pearson's r and Moran's I were combined with 9 types, and also quantile of L index value was used for each of those 9 types. Finally, these types were defined as 5 groups having not overlapped L index range. According to the application result of L index groups, bivariate water quality and nutrients showed no aspatial correlation regardless of spatial association in February and July, but they showed aspatial correlation having clustered spatial pattern in May and November. The result of this study providing the guideline for the interpretation of aspatial correlation and spatial association using L index is expected to be helpful for the marine environment pattern analysis using quantitative index for further study.

• Journal of Korean Medicine Rehabilitation
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• v.33 no.4
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• pp.185-193
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• 2023

Objectives This study was conducted to find out the correlation between lumbar malposition and lumbar disc herniation. Methods Among the patients who visited Gwangju Jaseng Hospital of Korean Medicine from January 2019 to January 2021, taking 92 patients under age 60 who had the records of X-rays and magnetic resonance imaging (MRI) images as the research subjects, Cobb's angle was measured in anterior-posterior (AP) view and lateral (LAT) view, the number of displacements was scored by listing categories defined by The Korean Society of Chuna Manual Medicine for Spine and Nerves. The degree of lumbar intervertebral disc herniation was expressed as a percentage according to the method of Kato, etc., and the correlation between each factor was analyzed. Results AP curvature and MRI herniation index showed significant positive correlation in L4-L5 level but there was no significant difference in L5-S1 level. LAT curvature and MRI herniation index had no correlation in L4-L5 level, but there was a significant negative correlation in L5-S1 level. Malposition score and MRI herniation index had a significant positive correlation in L5-S1 level, whereas there was no correlation in L4-L5. Conclusions As a result of the study, AP curvature and MRI herniation index showed a significant positive tendency in L4-L5 lumbar spine, and LAT curvature and MRI herniation index showed a significant negative tendency in L5-S1 lumbar spine. Malposition score and MRI herniation index were found to have a significant positive tendency in L5-S1 lumbar spine.

• Kyungpook Mathematical Journal
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• v.53 no.1
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• pp.117-124
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• 2013

We show that for 1 < $p$ < ${\infty}$, $k$, $m{\in}\mathbb{N}$, $n^{(k)}(l_p)=inf\{n^{(k)}(l^m_p):m{\in}\mathbb{N}\}$ and that for any positive measure ${\mu}$, $n^{(k)}(L_p({\mu})){\geq}n^{(k)}(l_p)$. We also prove that for every $Q{\in}P(^kl_p:l_p)$ (1 < $p$ < ${\infty}$), if $v(Q)=0$, then ${\parallel}Q{\parallel}=0$.