• 제목/요약/키워드: Central Difference

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The Intensification of Walker Circulation over the Past 15 Years from 1999 and Its Relation to TC Activity in the Western North Pacific

  • Choi, Jae-Won;Cha, Yumi;Kim, Jeoung-Yun
    • Journal of the Korean earth science society
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    • v.37 no.6
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    • pp.359-372
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    • 2016
  • The time-series of Walker circulation index (WCI) in this study shows the strengthening of the Walker circulation in recent years. To further understand the large-scale features related to the WCI strengthening, a difference between the averaged meteorological variables in two time periods 1999-2013 and 1984-1998 is analyzed. The difference in 850 hPa stream flows between the two periods shows that the anomalous easterlies (anomalous trade wind) are dominant due to the strengthening of anomalous anticyclonic circulations at the subtropical Pacific of both hemispheres. The difference between the averaged zonal atmospheric circulations over $5^oS-5^oN$ in the two periods confirms that upward flows are strengthened at the tropical western Pacific and downward flows are strengthened at the tropical central and eastern Pacific in recent years. It matches the WCI strengthening in recent years. The time-series of tropical cyclone (TC) genesis frequency from July to September shows that a mean TC genesis frequency from 1999-2013 decreases compared to that of the time period 1984-1998. The monsoon trough in the period 1984-1998 was located in the further east direction and stronger than that in the period 1999-2013. TCs in the recent period that are generated in further west than TCs in the past period moved from the west. Thus, the TC intensity along the coasts in East Asia becomes weaker in recent period. The intensification of Walker circulation in recent years is related to the weaker TC intensity in East Asia through strengthened anomalous anticyclones at the subtropical western Pacific.

Effectiveness of low-level laser therapy on recovery from neurosensory disturbance after sagittal split ramus osteotomy: a systematic review and meta-analysis

  • Firoozi, Parsa;Keyhan, Seied Omid;Kim, Seong-Gon;Fallahi, Hamid Reza
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.42
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    • pp.41.1-41.11
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    • 2020
  • Background: Orthognathic surgery such as bilateral sagittal split ramus osteotomy (BSSRO) for the treatment of mandibular deformities is one of the most common procedures in maxillofacial operations that may lead to neurosensory disturbance. In this study, we aimed to evaluate the effectiveness of low-level laser therapy (LLLT) on augmenting recovery of neurosensory disturbance of inferior alveolar nerve (IAN) in patients who underwent BSSRO surgery. Methods: A comprehensive literature search was conducted by two independent authors in PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), Scopus, Embase, and Google Scholar electronic databases. Besides, a manual search of all textbooks and relevant articles were conducted. Searches took place in August 2020 and were limited to published and peer-reviewed articles from 2000 to 2020. All analysis was performed using the comprehensive meta-analysis (CMA) and the STATA MP (version:16) software. The weighted mean difference (WMD) using the inverse variance method and the standard mean difference (SMD) was considered for continuous variables. Results: Seventy-four papers were retrieved after removing duplicate studies and finally, eight studies were assessed for qualitative synthesis and five for meta-analysis. Totally, 94 patients were included in the meta-analysis. Based on the meta-analysis, it was shown that LLLT was not effective in a short interval (0 to 48 h) after surgery, but in a period of more than 1 month after surgery, the positive results of treatment can be observed strikingly. Also, LLLT side/group showed no significant difference in some aspects of neurosensory recovery such as thermal sensation compared to the placebo side/group. Conclusions: The meta-analysis of randomized controlled trials revealed that LLLT generally improves IAN sensory disturbance caused by BSSRO. Further high-quality clinical trials with longer follow-up periods and larger sample sizes are recommended.

EphB1 and Ephrin-B, New Potential Biomarkers for Squamous Cell/adenosquamous Carcinomas and Adenocarcinomas of the Gallbladder

  • Yuan, Yuan;Yang, Zhu-Lin;Miao, Xiong-Ying;Liu, Zi-Ru;Li, Dai-Qiang;Zou, Qiong;Li, Jing-He;Liang, Lu-Feng;Zeng, Gui-Xiang;Chen, Sen-Lin
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.3
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    • pp.1441-1446
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    • 2014
  • Squamous cell/adenosquamous carcinoma (SC/ASC) of the gallbladder are rare tumors and there are few clinical reports in the literature. Herein we report our clinical experience with 46 patients with SC/ASC and 80 with adenocarcinoma (AC). Expression of EphB1 and Ephrin-B in each tumor was determined using immunohistochemical methods for determination of correlations with prognosis. There was no difference in EphB1 and Ephrin-B expression between SC/ASC and AC tumors (P>0.05), but greater expression in those less than 3 cm in diameter, stage I or II (TNM stage), with no lymph node metastases, with no local invasion and treated with radical resection was apparent. Expression of EphB1 (P<0.05) and Ephrin-B (P<0.01) was higher in well differentiated than in poorly differentiated AC tumors. Kaplan-Meier survival analysis indicated that degree of differentiation, tumor diameter, lymph node metastases, local invasion, surgical approach and expression rate of EphB1 and Ephrin-B were closely related to the survival of SC/ASC (P<0.05) and AC patients (P<0.01). Patients with tumors that positive expressed EphB1 and Ephrin-B, whether it is SC/ASC ($P_{SC/ASC}$ =0.000) or AC ($P_{AC}$ =0.000 or $P_{AC}$ =0.002) had longer survival than those negative expression. Cox multivariate analysis indicated a negative correlation between expression of EphB1 or Ephrin-B and overall survival. Hence, EphB1 and Ephrin-B could be regarded as independent good prognostic factorsand important biological markers for SC/ASC and AC of gallbladder.

Field Application of the Mass Concrete Utilizing Combined Method for Temperature Crack Reduction (온도균열 저감공법을 복합사용한 매스콘크리트의 현장적용)

  • Han, Sang-Yoon;Lee, Chung-Sub;Baek, Dae-Hyun;Jang, Duk-Bae;Han, Min-Cheol;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2010.05a
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    • pp.37-39
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    • 2010
  • In this study, with new office construction site of S Construction company as subject, to solve all the problems according to reduced hydration heat and temperature crack of mass concrete used mat foundation and placing time difference, low heat combination of coarse particle cement and fly-ash and setting time difference applied AE water reducing agent, and to prevent the early frost damage caused by low outdoor temperature, a heat insulation method using double bubble sheet was conducted. As a result, it was found that hydration heat and setting time difference was reduced by applying a low heat combination and setting time difference construction method, and that the high insulation capability of the double bubble sheet was able to not only prevent the early frost damage but also reduce temperature difference between the central part and the upper part of mass concrete.

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Image Retrieval Using Histogram Refinement Based on Local Color Difference (지역 색차 기반의 히스토그램 정교화에 의한 영상 검색)

  • Kim, Min-KI
    • Journal of Korea Multimedia Society
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    • v.18 no.12
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    • pp.1453-1461
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    • 2015
  • Since digital images and videos are rapidly increasing in the internet with the spread of mobile computers and smartphones, research on image retrieval has gained tremendous momentum. Color, shape, and texture are major features used in image retrieval. Especially, color information has been widely used in image retrieval, because it is robust in translation, rotation, and a small change of camera view. This paper proposes a new method for histogram refinement based on local color difference. Firstly, the proposed method converts a RGB color image into a HSV color image. Secondly, it reduces the size of color space from 2563 to 32. It classifies pixels in the 32-color image into three groups according to the color difference between a central pixel and its neighbors in a 3x3 local region. Finally, it makes a color difference vector(CDV) representing three refined color histograms, then image retrieval is performed by the CDV matching. The experimental results using public image database show that the proposed method has higher retrieval accuracy than other conventional ones. They also show that the proposed method can be effectively applied to search low resolution images such as thumbnail images.

An Analysis of Elastohydrodynamic Lubrication of Elliptical Contacts : Part II (타원접촉의 탄성유체윤활해석 : 제2보)

  • 박태조;현준수
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1999.06a
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    • pp.182-188
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    • 1999
  • A theoretical study of elastohydrodynamic lubrication of elliptical contacts with both rolling and spin has been carried out. A finite difference method and the Newton-Raphson method are applied to solve the problem. The velocity vectors resulting from combined spin and rolling/sliding motion lead to asymmetric pressure distributions and film shapes. Film contours and variations of the minimum and central film thicknesses are compared with various spin-roll ratios. At high spin-roll ratios the minimum film thickness is considerably reduced, whereas the central film thickness decreases less dramatically, The present numerical scheme can be used in the analysis of general elliptical contact problems.

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BLOOD PLASMA MINERALS AND FERTILITY OF DAIRY COWS IN CENTRAL THAILAND

  • Vijchulata, P.
    • Asian-Australasian Journal of Animal Sciences
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    • v.8 no.3
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    • pp.263-265
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    • 1995
  • Blood plasma minerals and their effects towards the fertility in 136 cows randomly selected from 26 dairy farms in central Thailand were studied. An average of 8.60 mg% Ca, 5.97 mg% P, 2.45 mg% Mg, $85.9{\mu}g%$ Cu, and $160.9{\mu}g%$ Zn in plasma was observed. Compared to the critical deficient values, 24.3, 10.3, 11.8, 28.7 and 0.0% of the surveyed cows obtained the respective elements in plasma below the standard levels. No significant difference (p >.05) in plasma concentrations of Ca, P, Mg and Zn for the low fertile (conception rate > 3) and fertile (conception rate < 3) cows was found. However, plasma Cu of the low fertile cows (averaged $77.2{\mu}g%$) was lower (p <.01) than that of the fertile ones (averaged $91.12{\mu}g%$). Additionally, it is observed that 47.1% of the cows with the low fertility problem obtained plasma Cu below the 65.0 pg% critical deficient value.

Difference in Chemotype Composition of Fusarium graminearum Populations Isolated from Durum Wheat in Adjacent Areas Separated by the Apennines in Northern-Central Italy

  • Prodi, A.;Purahong, W.;Tonti, S.;Salomoni, D.;Nipoti, P.;Covarelli, L.;Pisi, A.
    • The Plant Pathology Journal
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    • v.27 no.4
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    • pp.354-359
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    • 2011
  • Chemotype composition of Fusarium graminearum strains, isolated from durum wheat kernels from naturally FHB infected fields in Northern and Central Italy, was investigated by multiplex PCR. The different climatic and environmental conditions of the two examined areas separated by the Apennines affected the composition of chemotypes. 15Ac-DON chemotype was predominant in both the sub areas. Nivalneol chemotype was more frequent in the warmer sub area.

CHARACTERISTICS OF LOW LEVEL TEMPERATURE INVERSION IN TAIWAN

  • Liou Yuei-An;Yan Shiang-Kun
    • Proceedings of the KSRS Conference
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    • 2005.10a
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    • pp.38-41
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    • 2005
  • The observation data from MTP-5HE ofEPA are used to study the temperature inversion phenomenon in the lower boundary layer in Taipei, Taichung and Kaohsiung of Taiwan. Characteristics of temperature inversion at three cities are extracted using different classification methods. The characteristics of temperature inversion in Taichung and Kaohsiung show a similar trend but are different from that in Taipei. The numbers of the occurrence of temperature inversion in Taichung and Kaohsiung were much larger than that in Taipei. The main types of temperature inversion in Taiwan are radiation inversion and frontal inversion. Compared to frontal inversion, radiation inversion on average occurs at a lower altitude, lasts a longer period, has a deeper thickness, and reaches a higher temperature difference of inversion. Frontal inversion plays a significant role for the inversion event lasting over 12 hours.

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FUNCTIONAL CENTRAL LIMIT THEOREMS FOR MULTIVARIATE LINEAR PROCESSES GENERATED BY DEPENDENT RANDOM VECTORS

  • Ko, Mi-Hwa
    • Communications of the Korean Mathematical Society
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    • v.21 no.4
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    • pp.779-786
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    • 2006
  • Let $\mathbb{X}_t$ be an m-dimensional linear process defined by $\mathbb{X}_t=\sum{_{j=0}^\infty}\;A_j\;\mathbb{Z}_{t-j}$, t = 1, 2, $\ldots$, where $\mathbb{Z}_t$ is a sequence of m-dimensional random vectors with mean 0 : $m\times1$ and positive definite covariance matrix $\Gamma:m{\times}m$ and $\{A_j\}$ is a sequence of coefficient matrices. In this paper we give sufficient conditions so that $\sum{_{t=1}^{[ns]}\mathbb{X}_t$ (properly normalized) converges weakly to Wiener measure if the corresponding result for $\sum{_{t=1}^{[ns]}\mathbb{Z}_t$ is true.