• Title/Summary/Keyword: EAST Model

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Tracing the trajectory of pelagic Sargassum using satellite monitoring and Lagrangian transport simulations in the East China Sea and Yellow Sea

  • Kwon, Kyungman;Choi, Byoung-Ju;Kim, Kwang Young;Kim, Keunyong
    • ALGAE
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    • v.34 no.4
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    • pp.315-326
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    • 2019
  • Northeastward drifts of massive Sargassum patches were observed in the East China Sea (ECS) and Yellow Sea (YS) by the Geostationary Ocean Color Imager (GOCI) in May 2017. Coverage of the brown macroalgae patches was the largest ever recorded in the ECS and YS. Three-dimensional circulation modeling and Lagrangian particle tracking simulations were conducted to reproduce drifting trajectories of the macroalgae patches. The trajectories of the macroalgae patches were controlled by winds as well as surface currents. A windage (leeway) factor of 1% was chosen based on sensitivity simulations. Southerly winds in May 2017 contributed to farther northward intrusion of the brown macroalgae into the YS. Although satellite observation and numerical modeling have their own limitations and associated uncertainties, the two methods can be combined to find the best estimate of Sargassum patch trajectories. When satellites were unable to capture all patches because of clouds and sea fog in the ECS and YS, the Lagrangian particle tracking model helped to track and restore the missing patches in satellite images. This study suggests that satellite monitoring and numerical modeling are complementary to ensure accurate tracking of macroalgae patches in the ECS and YS.

Desulfurization of Model Oil via Adsorption by Copper(II) Modified Bentonite

  • Yi, Dezhi;Huang, Huan;Li, Shi
    • Bulletin of the Korean Chemical Society
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    • v.34 no.3
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    • pp.777-782
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    • 2013
  • In order to further reduce the sulfur content in liquid hydrocarbon fuels, a desulfurization process by adsorption for removing dimethyl sulfide (DMS) and propylmercaptan (PM) was investigated. Bentonite adsorbents modified by $CuCl_2$ for the desulfurization of model oil was investigated. The results indicated that the modified bentonite adsorbents were effective for adsorption of DMS and PM. The bentonite adsorbents were characterized by X-ray diffraction (XRD) and thermal analysis (TGA). The acidity was measured by FT-IR spectroscopy. Several factors that influence the desulfurization capability, including loading and calcination temperature, were studied. The maximum sulfur adsorption capacity was obtained at a Cu(II) loading of 15 wt %, and the optimum calcination temperature was $150^{\circ}C$. Spectral shifts of the ${\nu}$(C-S) and ${\nu}$(Cu-S) vibrations of the complex compound obtained by the reaction of $CuCl_2$ and DMS were measured with the Raman spectrum. On the basis of complex adsorption reaction and hybrid orbital theory, the adsorption on modified bentonite occurred via multilayer intermolecular forces and S-M (${\sigma}$) bonds.

Tides and Tidal Currents of the Yellow and East China Seas during the Last 13000 Years

  • Oh, Im-Sang;Lee, Dong-Eun
    • Journal of the korean society of oceanography
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    • v.33 no.4
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    • pp.137-145
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    • 1998
  • In order to investigate the paleotidal structure and current pattern in the Yellow and East China seas (YECS) since the late Wisconsin, which is the last glacial maximum period, a two-dimensional version of the Princeton ocean model is used. We assume that subtracting the sea-level differences from the present one can produce paleobasins and that the paleotide did not differ greatly from the present one in the adjacent deep seas, the northwestern Pacific Ocean and the East Sea. We could successfully simulate the paleo-M$_2$ tides and tidal currents of 9000, 11000 and 13000 yr B.P. The result of the model shows considerable differences in the tidal pattern in each period. As the eustatic sea level rose, the amplitudes of the paleotides and the number of the amphidromic points generally increased, but the tidal currents in each paleobasin were strong and about the same order as the present day's. Based on these paleotide calculations, we suggest that there should have been active erosion in the paleobasin as in the present YECS, and the erosion should have played an important role on widening the paleobasin to the present shape, YECS.

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Multivariate Causal Relationship between Stock Prices and Exchange Rates in the Middle East

  • Parsva, Parham;Lean, Hooi Hooi
    • The Journal of Asian Finance, Economics and Business
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    • v.4 no.1
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    • pp.25-38
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    • 2017
  • This study investigates the causal relationship between stock prices and exchange rates for six Middle Eastern countries, namely, Egypt, Iran, Jordan, Kuwait, Oman, and Saudi Arabia before and during (after) the 2007 global financial crisis for the period between January 2004 and September 2015. The sample is divided into two sub-periods, that is, the period from January 1, 2004 to September 30, 2007 and the period from October 1, 2007 to September 30, 2015, to represent the pre-crisis period and the post-crisis period, respectively. Using Vector Autoregressive (VAR) model in a multivariate framework (including two control variables, inflation rates and oil prices) the results suggest that in the case of Jordan, Kuwait and Saudi Arabia, there exists bidirectional causalities after the crisis period but not the before. The opposite status is available for the case of Iran. In the case of Oman, there is bidirectional causality between the variables of interest in both periods. The results also reveal that the relationship between stock prices and exchange rates has become stronger after the 2007 global financial crisis. Overall, the results of this study indicate that fluctuations in foreign exchange markets can significantly affect stock markets in the Middle East.

A Non-cooperative Game Theoretic Approach to Dust and Sand Storm in North East Asia

  • Song, Yang-Hoon
    • Journal of Environmental Policy
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    • v.6 no.3
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    • pp.91-114
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    • 2007
  • The cooperative cost sharing scheme for Dust and Sand Storm(DSS) in North East Asia, as suggested in Song and Nagaki(2007), may not be feasible due to possible defection(s) of participating countries. If non-cooperative strategies are more plausible, Nash equilibrium can suggest possible outcomes of the cost sharing game. The result from the continuous strategy model shows that there exists an infinite number of Nash equilibrium such that the summation of investment from each country is always equal to the required budget of the ADS pilot project. It is also discussed that the discrete strategy model points to only 3 Nash equilibria in continuous strategy game outcome and the cooperative game solution may be just one of the infinite equilibria.

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The Impact of Big Data Analytics on Audit Procedures: Evidence from the Middle East

  • ALRASHIDI, Mousa;ALMUTAIRI, Abdullah;ZRAQAT, Omar
    • The Journal of Asian Finance, Economics and Business
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    • v.9 no.2
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    • pp.93-102
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    • 2022
  • The goal of this study was to see how big data analytics (BDA) affected external audit procedures in the Middle East. The measurement model and structural model of this investigation were evaluated using PLS-SEM (3.3.3). The study sample members were (361) auditors who work in auditing companies in Kuwait, Saudi Arabia, the United Arab Emirates, Jordan, Bahrain, Egypt, Lebanon, and Iraq. A questionnaire was chosen to the study sample members electronically, and the study sample members were (5093) auditors who work in auditing companies in Kuwait, Saudi Arabia, the United Arab Emirates, Jordan, Bahrain, Egypt, Lebanon, and Iraq. To choose the sample, the researchers used a stratified random sampling procedure. The findings show that BDA has an impact on audit procedures at all phases of the auditing process, where it contributes to information delivery that helps auditors understand the client's internal and external environments, which in turn influences the choice to accept the audit assignment. Furthermore, by providing essential information, BDA enables auditors to simply run analytical procedures, estimate client risks, and understand and evaluate the internal control system. As a result, auditors must develop their abilities in the BDA field, as it adds to the creation of additional value for both auditors and their clients.

Measuring the Causal Relationships of Restaurant Service Quality and Perceived Sacrifice, Value, Satisfaction and Intention to Revisit in Tourist Area (관광지에서의 음식점 서비스 질, 지각된 희생, 가치, 만족과 재방문 의도의 인과 관계 평가)

  • Kang, Jong-Heon;Ko, Beom-Seok
    • Journal of the East Asian Society of Dietary Life
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    • v.17 no.4
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    • pp.580-588
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    • 2007
  • The purpose of this study was to measure the effects of the perceived sacrifice, service quality, value and satisfaction on the intention to revisit restaurants. A total of 273 questionnaires were completed. The equation model was used to measure the causal effects. The results demonstrated that the confirmatory factor analysis model provided an excellent model fit. The modified model yielded a significantly better fit to the data than the service quality model, and accounted for a greater share of the variance in intention to revisit than the service quality model. The effects of value and service quality on intention to revisit were statistically significant in both the service quality model and modified model. The effects of perceived sacrifice and service quality on value were statistically significant in the service quality model and modified model. As expected, service quality had a significant effect on satisfaction in the modified model. Satisfaction had a significant effect on intention to revisit in the modified model. Satisfaction also had a significant effect on service quality in the service quality model. Moreover, service quality had an indirect influence on intention to revisit through value and satisfaction in the modified model. Service quality had an indirect influence on the intention to revisit through value in the service quality model. The overall findings offer strong empirical support for the intuitive notion that improving service quality can increase favorable intention to revisit, and decrease unfavorable intention to revisit.

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Future Changes of Wildfire Danger Variability and Their Relationship with Land and Atmospheric Interactions over East Asia Using Haines Index (Haines Index를 이용한 동아시아 지역 산불 확산 위험도 변화와 지표-대기 상호관계와의 연관성 연구)

  • Lee, Mina;Hong, Seungbum;Park, Seon Ki
    • Atmosphere
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    • v.23 no.2
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    • pp.131-141
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    • 2013
  • Many studies have related the recent variations of wildfire regime such as the increasing number of occurrances, their patterns and timing changes, and the severity of their extreme cases with global warming. However, there are only a few numbers of wildfire studies to assess how the future wildfire regime will change in the interactions between land and atmosphere with climate change especially over East Asia. This study was performed to estimate the future changing aspect of wildfire danger with global warming, using Haines Index (HI). Calculated from atmospheric instability and dryness, HI is the potential of an existing fire to become a dangerous wildfire. Using the Weather Research and Forecasting (WRF) model, two separated 5-year simulations of current (1995~1999) and far future (2095~2099) were performed and analyzed. Community Climate System Model 3 (CCSM3) model outputs were utilized for the model inputs for the past and future over East Asia; future prediction was driven under the IPCC A1B scenario. The results indicate changes of the wildfire danger regime, showing overall decreasing the wildfire danger in the future but intensified regional deviations between north and south. The overall changes of the wildfire regime seems to stem from atmospheric dryness which is sensitive to soil moisture variation. In some locations, the future wildfire danger overall decreases in summer but increases in winter or fall when the actual fire occurrence are generally peaked especially in South China.

Research Trends on the 'Convergence of Chinese and Western Medicine' in China, and Lessons Learned (중국의 중서의회통파에 대한 연구동향과 한국 한의계가 얻을 수 있는 교훈)

  • Lee, Choong-Yeol
    • The Journal of Korean Medical History
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    • v.30 no.2
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    • pp.13-31
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    • 2017
  • This study investigates research trends on the Convergence of Chinese and Western Medicine (中西醫匯通, CCWM), by first defining the concepts and the scope of this emerging field, identifying different types of convergence, and suggesting methods to evaluate the process. The author investigates the relationship of CCWM to the Self-Strengthening Movement and the doctrine of Zhongtixiyong (中體西用). Lessons that Korean Medicine (KM) can learn from this approachto help establish relationship between Korean and Western Medicine, are investigated. Proponents of CCWM suggest different types of convergence such as Zhongzhongcanxi (衷中參西), Zhongxizhezhong (中西折衷), and ZhongyiKexuehua (中醫科學化), to accommodate the change in the power dynamics between Chinese and Western medicines. The rigid dual medical system in Korea significantly hinders the potential for convergence. The current system is based on the relativistic model in which the scope of practice for the KM doctor and the Western Medicine doctor are mutually exclusive. Philosophically, the convergence of East-West medicine can be supported by pluralism and monism, while relativism sees it as impossible. A conservative pluralistic model might consider Bogu (補救) of Eastern Medicine, while a more progressive pluralistic model might build a New Medicine which combines the knowledge and techniques of Eastern and Western medicines. An example of monistic model is CAM (Complementary and Alternative Medicine), which aims to scientifically verify the efficacy and safety of the Eastern therapeutic practices and integrate them into Western medicine. This article proposes that as communication and fusion between medical disciplines are essential virtues of contemporary scholarly development, a change that enables the convergence of East-West medicine is needed.

Comparison of nonlinear 1$1/2$-layer and 2$1/2$-layer numerical models with strong offshore winds and the Tsushima Current in the East Sea

  • Kim, Soon-Young;Lee, Hyong-Sun;Dughong Min;Yoon, Hong-Joo
    • Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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    • v.3 no.2
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    • pp.91-103
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    • 1999
  • According to numerical experiments, the Sokcho Eddy is produced at $37 5~39.0^{\circ}N$ by strong offshore winds, whereas the Ulleung Eddy is produced at $35~37^{\circ}N$ by an inflow variation of the Tsushima Current. These locations compare well with visual observations. The nonlinear 1$1/2$-layer model showed that most of the East Korea Warm Current (EKWC) driven by the Tsushima Current form the Ulleung Eddy that is larger and stronger than the Sokcho Eddy. In contrast, the nonlinear 2$1/2$-layer model showed that most of the EKWC travels further northward due to a strong subsurface current, thereby enhancing the Sokcho Eddy making it larger and stronger than the Ulleung Eddy. The Sokcho Eddy is also produced relatively offshore due to an eastward subsurface current in the frontal region. Using the 1$1/2$-layer model, when the mass of the Tsushima Current decreases, the two eddies are weakened and produce a circular shape. In the 2$1/2$-layer model the EKWC pushes the Ulleung Eddy northward after 330 days, next the Sokcho and Ulleung eddies begin to interact with each other, and then after 360 days the Ulleung Eddy finally disappears absorbed by the relatively stronger Sokcho Eddy. This behavior compares favorably with other visual observations.

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