• Title/Summary/Keyword: global correlation

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Meta-Analysis of Correlation Between Subjective and Objective Cognitive-Linguistic Tests : Focused on Normal Aging, MCI, and Dementia (메타분석을 통한 주·객관적 인지-언어 평가 간 상관성 연구 : 정상 노년층, MCI, 치매 환자를 중심으로)

  • Lee, Mi-Sook
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.11
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    • pp.7414-7423
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    • 2015
  • Subjective cognitive-linguistic complaints in older adults contribute to the diagnostic and prognostic investigation of MCI or dementia. However, the utility of subjective test for predicting cognitive-linguistic decline is controversial. Few domestic studies have included the correlation between subjective and objective tests systematically. The current study analyzed 26 studies published since 2000, and the effect sizes of their correlation coefficients between two tests were computed. The results of qualitative analysis indicated that the number of subjects ranged from 26 to 657. Subjective tests included the self-report 75.4% and the informant-report 24.6%. In objective tests, memory comprised the largest proportion, followed by global cognition, and language, etc. As a result of meta-analysis, self-report test had the predictive value for dementia, and informant-report test contributed to discriminate among 3 groups. In the elderly group, self-report test was correlated with reasoning, and informant-report test with memory and language. In MCIs, self-report test predicted several abilities including language, and informant-report test signaled the future decline of domains like global cognition. Two types of subjective tests in dementia also represented memory, language, and global cognition accurately. This study provides evidence-based information to support relationships between subjective and objective tests for cognitive-linguistic ability in 3 groups.

Spatial Correlation Analysis of the Mean Sea Level Data Sets in the Coastal Seas, Korea (한국 연안 평균 해수면 자료의 공간 상관관계 분석)

  • Cho, Hong-Yeon;Jeong, Shin Taek;Lee, Uk Jae
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.32 no.1
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    • pp.85-93
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    • 2020
  • The basic information of mean sea level data of all tidal monitoring stations in Korea was reviewed, and the correlation coefficients between the stations were analyzed. Mean sea level changes expected due to global climate change effects were found to show a high correlation of more than 0.75 regardless of the distance between the stations were analyzed. The data between certain stations were found to have negative correlation and low correlation of 0.25 or less, but this was determined by the influence of small data numbers and outliers. However, since these correlations assume a linear increase and a linear relationship, the estimation results may be distorted for data with fluctuating trends that deviate from this assumption. Based on the results of the changing patterns of the MSL data, it shows that a number of the MSL data do not follow the linear trend.

Characteristics of Environmental Solar Ultraviolet Irradiance

  • Sasaki, Masako;Oyanagi, Takehiko;Takeshita, Shu
    • Journal of Photoscience
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    • v.9 no.2
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    • pp.154-157
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    • 2002
  • Direct, continuous, and accurate measurements of solar ultraviolet irradiance (290-400 nm: UVR) have been carried out since 1990, by using both band-spectral ultraviolet-B (290-320 nm: UV-B) and ultraviolet-A (320-400 nm: UV-A) radiometers at Tokai University in Hiratsuka, Japan (35$^{\circ}$N, 139$^{\circ}$E). From our observations, the following findings are provided: 1) an increasing trend in solar UV -B from Oct. 1990 to Sept. 2000; 2) a regional comparison of solar UVR in Japan; 3) the distinct characteristics of UV-B and UV-A irradiance, such as diffuse property, daily and seasonal variation; and 4) human body protection against solar UVR. An increasing 10-year trend in global solar UV - B in Hiratsuka corresponded to a decrease in the total ozone amount measured at Tsukuba (36$^{\circ}$N, 140$^{\circ}$E), giving supportive evidence for a direct link between these two parameters. Furthermore, a strong correlation was found between solar UV-B and total ozone amount from results of UVR measurements at four Tokai University monitoring stations dispersed throughout Japan. Additional results revealed different diffuse properties in global solar UV and in global solar total (300-3000 nm: Total) irradiances. For example, in the global UVR, the diffuse component was dominant: about 80 % independent of weather, with more than 60 % of global UV-B, and more than 50% of global UV-A with even a cloudless clear sky. On the other hand, the portion of the diffuse in the global total irradiance was very low, less than 10 % on a cloudless clear day. Daily and seasonal variations of UV -B and UV -A irradiances were found to be quite different, because of the marked dependence of UV -B irradiance on the atmospheric ozone amount. Moreover, UV -B irradiance showed large daily and seasonal variations: the ratio between maximum and minimum irradiances was more than 5. In contrast, the variation in UV-A was small: the ratio between maximum and minimum was less than 2. Three important facts are proposed concerning solar UVR protection of the human body: 1) the personal minimal erythema dose (MED); 2) gender based difference in MED values; and 3) proper colors for UVR protective clothing.

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A Prediction of Northeast Asian Summer Precipitation Using Teleconnection (원격상관을 이용한 북동아시아 여름철 강수량 예측)

  • Lee, Kang-Jin;Kwon, MinHo
    • Atmosphere
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    • v.25 no.1
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    • pp.179-183
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    • 2015
  • Even though state-of-the-art general circulation models is improved step by step, the seasonal predictability of the East Asian summer monsoon still remains poor. In contrast, the seasonal predictability of western North Pacific and Indian monsoon region using dynamic models is relatively high. This study builds canonical correlation analysis model for seasonal prediction using wind fields over western North Pacific and Indian Ocean from the Global Seasonal Forecasting System version 5 (GloSea5), and then assesses the predictability of so-called hybrid model. In addition, we suggest improvement method for forecast skill by introducing the lagged ensemble technique.

The Risk Assessment Effects of SCM and the Strategy of Risk Management on Supply Chain Performance (공급사슬 위험평가 및 위험관리전략이 공급사슬 운영성과에 미치는 영향)

  • Kim, Dong Jeong;Lee, Young Jai
    • Journal of Information Technology Applications and Management
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    • v.21 no.4
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    • pp.173-186
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    • 2014
  • This study outlines possible risk factors in the SCM of a company and correlates risk assessment, the strategy of risk management, and the supply chain performance. The data is surveyed from an international Korean company and is analyzed by the structure equation model of actual proof. The research model verifies the correlation between the risk assessment, the strategy of risk management, and the supply chain performance as dependent variables after the risk factors of the SCM are defined as independent variables. The research shows that there are consecutive links among the risk factors of the SCM, the risk assessment, and the strategy of risk management. The strategy of risk management was conclusively determined to have an effect on supply chain performance. Therefore, improving the supply chain performance of a company requires the constructive process for risk management based on a correlation between risk assessment and the strategy of risk management.

Study on the Relationship between Ownership Structure and Environmental Information Disclosure in GRI Reports (GRI 보고서 상의 환경정보 공시수준과 소유구조와의 관계)

  • Bae, Seong Mi;Han, Tae Il;Kim, Jong Dae
    • Journal of Environmental Science International
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    • v.27 no.8
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    • pp.701-709
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    • 2018
  • Few prior studies investigated the correlation between corporate ownership structure and environmental information disclosure. Using environmental index disclosure in GRI (Global Reporting Initiative) reports of the Korean companies, the study examines the effects of ownership structure on the magnitude of environmental information disclosure. A total of 220 firm-years during 2013-2016 period are analyzed. The empirical results of the study indicate that the institutional and foreign investors' ownership have positive correlations with environmental information disclosure, while the executives' within board of directors has a negative correlation. The ownership by largest shareholders including those with special interests shows no significant relationship with the environmental information disclosure.

Flame Diagnosis using Image Processing Technique (영상처리 기술을 이용한 연소상태 진단)

  • Lee, Tae-Young;Kim, Song-Hwan;Lee, Sang-Ryong
    • Journal of the Korean Society for Precision Engineering
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    • v.16 no.7
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    • pp.196-202
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    • 1999
  • Recent trend changes a criterion for evaluation of burner that environmental problem is raised as global issue. For efficient driving problem, the higher thermal efficiency and the lower oxygen in exhaust gas, burner is evaluated the better. For environmental problem, burner must satisfy $NO_{X}$ limit and CO limit. Consequently, 'good burner' means on whose thermal efficiency is high under the constraint of $NO_{X}$ and CO consistency. To make existing burner satisfy recent criterion, it is highly recommended to develop feedback control scheme whose output is the consistency of $NO_{X}$ and CO. This paper describes development of real time flame diagnosis technique that evaluate and diagnose combustion state such as consistency of components in exhaust gas, stability of flame in quantitative sense. This study focuses on wave length of luminescence from chemical reaction measurement of the luminescence via optical measuring apparatus and derive correlation with consistency of components in exhaust gas by image processing technique.

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Stationary random response analysis of linear fuzzy truss

  • Ma, J.;Chen, J.J.;Gao, W.;Zhao, Y.Y.
    • Structural Engineering and Mechanics
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    • v.22 no.4
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    • pp.469-481
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    • 2006
  • A new method called fuzzy factor method for the stationary stochastic response analysis of fuzzy truss with global fuzzy structural parameters is presented in this paper. Considering the fuzziness of the structural physical parameters and geometric dimensions simultaneously, the fuzzy correlation function matrix of structural displacement response in time domain is derived by using the fuzzy factor method and the optimization method, the fuzzy mean square values of the structural displacement and stress response in the frequency domain are then developed with the fuzzy factor method. The influences of the fuzziness of structural parameters on the fuzziness of mean square values of the displacement and stress response are inspected via an example and some important conclusions are obtained. Finally, the example is simulated by Monte-Carlo method and the results of the two methods are close, which verified the feasibility of the method given in this paper.

P-${\Delta}$ Effects on the Reliability of Offshore Platforms

  • Leon, David-De;Dante Campos
    • Computational Structural Engineering : An International Journal
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    • v.3 no.1
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    • pp.31-37
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    • 2003
  • A typical marine platform in the Bay of Campeche is studied from the standpoint of structural reliability, and several characteristics of its deck such as slenderness and diameter/thickness ratios of the legs and actual degree of correlation between some variables are taken into account. The global and local buckling capacities of the deck legs are compared and the correlation coefficient between the critical axial load and the critical moment is assessed in order to validate its influence on the structural reliability. In addition, the influence of the vertical load, and its uncertainty, on the variance of the decks capacity, and latter on, on the platform's failure probability is assessed. The results presented may be used in future studies to further extend and upgrade the first version of the Reference Norm (PEMEX, 2000) and, in the longer term, to improve the current practice in the Design and Requalification of Offshore Marine Platforms in the Bay of Campeche.

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Time-varying Co-movements and Contagion Effects in Asian Sovereign CDS Markets

  • Cho, Daehyoung;Choi, Kyongwook
    • East Asian Economic Review
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    • v.19 no.4
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    • pp.357-379
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    • 2015
  • We investigate interconnectedness and the contagion effect of default risk in Asian sovereign CDS markets since the global financial crisis. Using dynamic conditional correlation analysis, we find that there are significant co-movements in Asian sovereign CDS markets; that such co-movements tend to be larger between developing countries than between developed and developing countries; and that in the co-movements intra-regional nature is stronger than inter-regional nature. With the Spillover Index model, we measure contagion probabilities of sovereign default risk in CDS markets of seven Asian countries and find evidence of contagion effects among six of them; Japan is the exception. In addition, we find that these six countries are affected more by cross-market spillovers than by their own-market spillovers. Furthermore, a rolling-sample analysis reveals that contagion in the Asian sovereign CDS markets expands during episodes of extreme economic and financial distress, such as the Lehman Brothers bankruptcy, the European financial crisis, and the US-credit downgrade.