• Title/Summary/Keyword: correlation feature analysis

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Assessment of Water Quality in Namdae-Stream, Yeongok-Stream and Sacheon-Stream Using Trophic Status and Epilithic Diatom Indices (부착규조지수와 영양단계 평가를 이용한 남대천, 연곡천과 사천천의 수질 평가)

  • Kim, Yong-Jin;Lee, Ok-Min
    • Korean Journal of Ecology and Environment
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    • v.43 no.1
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    • pp.117-128
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    • 2010
  • The water qualities of Namdae-stream, Yeongok-stream and Sacheon-stream were examined, by using physicochemical factors, trophic status and epilithic diatoms from May 2008 to February 2009. The physicochemical water qualities of three streams were, except for some construction areas and sites of downstream, generally good, having less concentration than BOD of $2\;mg\;L^{-1}$. As for the sites of downstream, there were ongoing pollution such as graduation of nutrients in Namdae-stream and Sacheon-stream, due to salinity of seawater and topographical feature of the closed estuary. The examination of trophic status of Namdae-stream showed mesotrophic status in all the sites. Also, eutrophication was in progress as from the upstream to the downstream of Yeongok-stream, and Sacheon-stream showed eutrophic status in all its sites. As a result of the biological water quality assessment, Namdae-stream, excluding the downstream site, came out to be $\beta\sim\alpha$-oligosaprobic, and biological water quality was good, having TDI less than 50. Some construction sites and downstream site of Namdae-stream are $\beta$-mesosaprobic, and with the TDI over 70, the biological water quality assessment came out to be polluted. Yeongok-stream is $\beta\sim\alpha$-oligosaprobic, and its biological water quality is good, having TDI less than 40. Sacheon-stream, excluding the upstream site on May 2008 and February 2009, is $\beta\sim\alpha$-mesosaprobic, and its TDI over 70 shows that it has been polluted. The correlation analysis showed a high correlation in both DAlpo and TDI. Also, biological assessment of water quality (DAIpo, TDI) showed higher correlation with TSI rather than BOD.

Present-Day Climate of the Korean Peninsula Centered Northern East Asia Based on CMIP5 Historical Scenario Using Fine-Resolution WRF (CMIP5 Historical 시나리오에 근거한 WRF를 이용한 한반도 중심의 동북아시아 상세기후)

  • Ahn, Joong-Bae;Hong, Ja-Young;Seo, Myung-Suk
    • Atmosphere
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    • v.23 no.4
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    • pp.527-538
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    • 2013
  • In this study, climate over Korea based on the Historical scenario induced by HadGEM2-AO is simulated by WRF. For this purpose, a system that can be used be for numerical integration over the Far East Asian area of the center of the Korean Peninsula with 12.5 km-horizontal resolution was set-up at "Haebit", the early portion of KMA Supercomputer Unit-3. Using the system, the downscaling experiments were conducted for the period 1979-2010. The simulated results of HadGEM2-AO and WRF are presented in terms of 2 m-temperature and precipitation during boreal summer and winter of Historical for the period 1981~2005, compared with observation. As for the mean 2 m-temperature, the general patterns of HadGEM2-AO and WRF are similar with observation although WRF showed lower values than observation due to the systematic bias. WRF reproduced a feature of the terrain-following characteristics reasonably well owing to the increased horizontal resolution. Both of the models simulated the observed precipitation pattern for DJF than JJA reasonably, while the rainfall over the Korean Peninsula in JJA is less than observation. HadGEM2-AO in DJF 2 m-temperature and JJA precipitation has warm and dry biases over the Korean Peninsula, respectively. WRF showed cold bias over JJA 2 m-temperature and wet bias over DJF precipitation. The larger bias in WRF was attributed to the addition of HadGEM2-AO's bias to WRF's systematic bias. Spatial correlation analysis revealed that HadGEM2-AO and WRF had above 0.8 correlation coefficients except for JJA precipitation. In the EOF analysis, both models results explained basically same phase changes and variation as observation. Despite the difference in mean and bias fields for both models, the variabilities of the two models were almost similar with observation in many respects, implying that the downscaled results can be effectively used for the study of regional climate around the Korean Peninsula.

An Analysis of Similarity Measures for Area-based Multi-Image Matching (다중영상 영역기반 영상정합을 위한 유사성 측정방법 분석)

  • Noh, Myoung-Jong;Kim, Jung-Sub;Cho, Woo-Sug
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.30 no.2
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    • pp.143-152
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    • 2012
  • It is well-known that image matching is necessary for automatic generation of 3D data such as digital surface data from aerial images. Recently developed aerial digital cameras allow to capture multi-strip images with higher overlaps and less occluded areas than conventional analogue cameras and that much of researches on multi-image matching have been performed, particularly effective methods of measuring a similarity among multi-images using point features as well as linear features. This research aims to investigate similarity measuring methods such as SSD and SNCC incorporated into a area based multi-image matching method based on vertical line locus. In doing this, different similarity measuring entities such as grey value, grey value gradient, and average of grey value and its gradient are implemented and analyzed. Further, both dynamic and pre-fixed adaptive-window size are tested and analyzed in their behaviors in measuring similarity among multi-images. The aerial images used in the experiments were taken by a DMC aerial frame camera in three strips. The over-lap and side-lap are about 80% and 60%, respectively. In the experiment, it was found that the SNCC as similarity measuring method, the average of grey value and its gradient as similarity measuring entity, and dynamic adaptive-window size can be best fit to measuring area-based similarity in area based multi-image matching method based on vertical line locus.

Prediction of Key Variables Affecting NBA Playoffs Advancement: Focusing on 3 Points and Turnover Features (미국 프로농구(NBA)의 플레이오프 진출에 영향을 미치는 주요 변수 예측: 3점과 턴오버 속성을 중심으로)

  • An, Sehwan;Kim, Youngmin
    • Journal of Intelligence and Information Systems
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    • v.28 no.1
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    • pp.263-286
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    • 2022
  • This study acquires NBA statistical information for a total of 32 years from 1990 to 2022 using web crawling, observes variables of interest through exploratory data analysis, and generates related derived variables. Unused variables were removed through a purification process on the input data, and correlation analysis, t-test, and ANOVA were performed on the remaining variables. For the variable of interest, the difference in the mean between the groups that advanced to the playoffs and did not advance to the playoffs was tested, and then to compensate for this, the average difference between the three groups (higher/middle/lower) based on ranking was reconfirmed. Of the input data, only this year's season data was used as a test set, and 5-fold cross-validation was performed by dividing the training set and the validation set for model training. The overfitting problem was solved by comparing the cross-validation result and the final analysis result using the test set to confirm that there was no difference in the performance matrix. Because the quality level of the raw data is high and the statistical assumptions are satisfied, most of the models showed good results despite the small data set. This study not only predicts NBA game results or classifies whether or not to advance to the playoffs using machine learning, but also examines whether the variables of interest are included in the major variables with high importance by understanding the importance of input attribute. Through the visualization of SHAP value, it was possible to overcome the limitation that could not be interpreted only with the result of feature importance, and to compensate for the lack of consistency in the importance calculation in the process of entering/removing variables. It was found that a number of variables related to three points and errors classified as subjects of interest in this study were included in the major variables affecting advancing to the playoffs in the NBA. Although this study is similar in that it includes topics such as match results, playoffs, and championship predictions, which have been dealt with in the existing sports data analysis field, and comparatively analyzed several machine learning models for analysis, there is a difference in that the interest features are set in advance and statistically verified, so that it is compared with the machine learning analysis result. Also, it was differentiated from existing studies by presenting explanatory visualization results using SHAP, one of the XAI models.

Enhancement of Inter-Image Statistical Correlation for Accurate Multi-Sensor Image Registration (정밀한 다중센서 영상정합을 위한 통계적 상관성의 증대기법)

  • Kim, Kyoung-Soo;Lee, Jin-Hak;Ra, Jong-Beom
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.42 no.4 s.304
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    • pp.1-12
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    • 2005
  • Image registration is a process to establish the spatial correspondence between images of the same scene, which are acquired at different view points, at different times, or by different sensors. This paper presents a new algorithm for robust registration of the images acquired by multiple sensors having different modalities; the EO (electro-optic) and IR(infrared) ones in the paper. The two feature-based and intensity-based approaches are usually possible for image registration. In the former selection of accurate common features is crucial for high performance, but features in the EO image are often not the same as those in the R image. Hence, this approach is inadequate to register the E0/IR images. In the latter normalized mutual Information (nHr) has been widely used as a similarity measure due to its high accuracy and robustness, and NMI-based image registration methods assume that statistical correlation between two images should be global. Unfortunately, since we find out that EO and IR images don't often satisfy this assumption, registration accuracy is not high enough to apply to some applications. In this paper, we propose a two-stage NMI-based registration method based on the analysis of statistical correlation between E0/1R images. In the first stage, for robust registration, we propose two preprocessing schemes: extraction of statistically correlated regions (ESCR) and enhancement of statistical correlation by filtering (ESCF). For each image, ESCR automatically extracts the regions that are highly correlated to the corresponding regions in the other image. And ESCF adaptively filters out each image to enhance statistical correlation between them. In the second stage, two output images are registered by using NMI-based algorithm. The proposed method provides prospective results for various E0/1R sensor image pairs in terms of accuracy, robustness, and speed.

Cell Death-Associated Ribosomal RNA Cleavage in Postmortem Tissues and Its Forensic Applications

  • Kim, Ji Yeon;Kim, Yunmi;Cha, Hyo Kyeong;Lim, Hye Young;Kim, Hyungsub;Chung, Sooyoung;Hwang, Juck-Joon;Park, Seong Hwan;Son, Gi Hoon
    • Molecules and Cells
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    • v.40 no.6
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    • pp.410-417
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    • 2017
  • Estimation of postmortem interval (PMI) is a key issue in the field of forensic pathology. With the availability of quantitative analysis of RNA levels in postmortem tissues, several studies have assessed the postmortem degradation of constitutively expressed RNA species to estimate PMI. However, conventional RNA quantification as well as biochemical and physiological changes employed thus far have limitations related to standardization or normalization. The present study focuses on an interesting feature of the subdomains of certain RNA species, in which they are site-specifically cleaved during apoptotic cell death. We found that the D8 divergent domain of ribosomal RNA (rRNA) bearing cell death-related cleavage sites was rapidly removed during postmortem RNA degradation. In contrast to the fragile domain, the 5' terminal region of 28S rRNA was remarkably stable during the postmortem period. Importantly, the differences in the degradation rates between the two domains in mammalian 28S rRNA were highly proportional to increasing PMI with a significant linear correlation observed in mice as well as human autopsy tissues. In conclusion, we demonstrate that comparison of the degradation rates between domains of a single RNA species provides quantitative information on postmortem degradation states, which can be applied for the estimation of PMI.

AIDS-Related Non-Hodgkin Lymphoma: Imaging Feature Analysis of 27 Cases and Correlation with Pathologic Findings

  • Yang, Jun;Wang, Peng;Lv, Zhi-Bin;Wei, Lian-Gui;Xu, Yun-Liang;Zhou, An;Xu, Dong-Hai;Ma, Da-Qing
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.18
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    • pp.7769-7773
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    • 2014
  • Background: Some tumor types are related to HIV, including non-Hodgkin lymphoma (NHL). The morbidity and mortality of NHL has remained high, even after highly active antiretroviral therapy (HAART) was introduced. We collected cases of AIDS with NHL, and evaluated the imaging features and strategies for diagnosis. Materials and Methods: There were 27 patients with AIDS and tumors confirmed by pathology. There were 9 patients with Burkitt lymphoma, 16 with diffuse large B cell lymphomas (DLBCLs), and 2 with primary central nervous system (PCNS) lymphomas. All of the patients underwent a series of imaging studies. Three radiologists analyzed the images, and any disagreement was discussed until consensus was reached. Results: The radiologic manifestations of AIDS with NHL were mainly masses and lymphadenopathy, 3 patients having one mass and 12 two or more masses. 7 patients had lymphadenopathy in one site and 3patients had lymphadenopathy in two or more sites. Coarse mucosal folds, thickening of the gastrointestinal wall, and lumen narrowing were typical manifestations of NHL within the gastrointestinal tract. There were 4 patients with masses and 5 with lymphadenopathy inthe 9 with Burkitt lymphoma, and 11 patients with masses 5 with lymphadenopathy in the 16 with DLBCLs. Conclusion: NHL is a malignancy that usually occurs in patients with AIDS. Imaging is an important method by which to evaluate lesions, masses, and lymphadenopathy. Fine needle aspiration biopsy and stereotaxis biopsy are useful methods by which to diagnose NHL.

Morphological Analysis of the Myelinated Parent Axons that Innervate Rat Upper Molar Pulps in the Trigeminal Ganglion

  • Paik, Sang Kyoo;Kim, Jong Ho;Kim, Tae Heon;Bae, Yong Chul
    • International Journal of Oral Biology
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    • v.40 no.4
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    • pp.175-182
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    • 2015
  • Previous studies suggested that myelinated axons innervating rat molar pulps undergo morphological changes in their peripheral course. However, little information is available on the morphological feature of the parent axons at the site of origin. We therefore investigated the size of the myelinated parent axons and their morphological features at the proximal sensory root of the trigeminal ganglion by horseradish peroxidase (HRP) injection into rat upper molar pulps and subsequent light and electron microscopy. A total of 248 HRP-labeled myelinated axons investigated were highly variable in the size. Fiber area, fiber diameter, axon area (axoplasm area), axon diameter (axoplasm diameter), and myelin thickness were $11.32{\pm}8.36{\mu}m^2(0.80{\sim}53.17{\mu}m^2)$, $3.99{\pm}1.53{\mu}m(1.08{\sim}9.26{\mu}m)$, $8.70{\pm}6.30{\mu}m^2(0.70{\sim}41.83{\mu}m^2)$, $3.13{\pm}1.13{\mu}m(0.94{\sim}7.20{\mu}m)$ and $0.43{\pm}0.23{\mu}m(0.07{\sim}1.06{\mu}m)$, respectively. The g-ratio (axon diameter / fiber diameter) of the labeled axons was $0.79{\pm}0.05$ (0.61~0.91). Axon diameter was highly correlated with myelin thickness (correlation coefficients, r=0.83) but little correlated with g-ratio (r=-0.33) of individual myelinated parent axons. These results indicate that myelin thickness of the myelinated parent axons innervating rat molar pulps increase with increasing axon diameter, thus maintaining a constant g-ratio.

Effect on Social Game Use on the Degree of Social Capital - Based on Construal Level Theory - (소셜게임 이용시간이 사회자본에 미치는 영향에 대한 연구 - 해석수준 이론을 중심으로 -)

  • Lee, Dae Young;Ryu, Seoung Ho;Jeong, Eui Jun
    • Journal of Korea Game Society
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    • v.13 no.6
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    • pp.65-74
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    • 2013
  • There are a number of studies about the impact of social games' social network. But because of conflicting results, the game's effect isn't ascertained. In this study, we defined that using social games makes increase the social capital with construal level theory. The survey results on construal level, social capital, game using time, etc, are used for the analysis of the correlation and interact. As a result, growing bridging social capital shows on the people who use high level of construal and more social game time use. This phenomenon did not appear in other online games, so that makes a social games' feature unique characteristic. And we discovered that high level construals is key point for defining the practical use of media.

Correlation between Building Facade Elements and Defects through "Pixelization Method" (픽셀화기법을 통한 건축물 외벽의 하자와 입면 구성 요소 간의 관계 분석)

  • Kim, Wooram;Jeon, Yongdeok;Shin, Jeongran;Jeong, Kichang;Lee, Jaeseob
    • Korean Journal of Construction Engineering and Management
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    • v.17 no.4
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    • pp.40-48
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    • 2016
  • The construction industry has been made diversified on the design process depending on qualitative growth of customers' demands. But this approach has lead to problems such as falling of building values due to lack of awareness of defects caused by long term utilization. So, the relationship on the characteristics of buildings and defects should be clearly analyzed to prevent falling of building values. This study, therefore, proposed a technique to quantify the relationship between building facade elements and defects. The technique was developed by applying pixel concept to the outside of the buildings. It has a feature to determine the clear relationship by presenting quantitative data that have been recognized qualitatively. The proposed technique is referred to "Pixelization Method". It separates building facade into unit compartment and makes database by assigning a code depending on the characteristics. Through the method, this study is expected to create a foundation for the quantitative analysis of relationship between building facade elements and defects as a basis on active responding to the defects.