• Title/Summary/Keyword: FAVOR method

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Predictive model for wave-induced currents and 3D beach evolution based on FAVOR Method

  • Kuroiwa, Masamitsu;Abualtayef, Mazen;Takada, Tetsushi;Sief, Ahmed Khaled;Matsubara, Yuehi
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.2 no.2
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    • pp.68-74
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    • 2010
  • The development of a numerical model using the fractional area/volume obstacle representation (FAVOR) method for predicting a nearshore current field bounded by complicated geometric shapes, and a three-dimensional (3D) beach evolution was described in this article. The 3D model was first tested against three cases to simulate the nearshore current fields around coastal structures, a river mouth, and a large scale cusp bathymetry. Then, the morphodynamic model tests, which are adopting the nearshore current model, were applied for the computations of beach evolution around a detached breakwater and two groins. It was confirmed that the presented model associated with the FAVOR method was useful to predict the nearshore current field in the vicinity of the complicated geometric shapes. Finally, the model was applied to a tombolo formation in a field site of Kunnui fishery port, which is located in Hokkaido, Japan.

Detecting Differential Item Functioning based on Gender: Field of Mathematics in the TIMSS 2007 (초등학생의 성별에 따른 차별기능문항 분석: 수학 과학 성취도 국제비교연구(TIMSS) 2007 수학영역을 중심으로)

  • LEE, Seungbae;KIM, Sukwoo
    • Journal of Fisheries and Marine Sciences Education
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    • v.29 no.3
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    • pp.757-766
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    • 2017
  • This study investigated not only the existence of differently functioned item due to gender but also domain. In this study, the randomly selected data of TIMSS 2007, which consist of 681 male and 646 women, were analyzed. To detect differently functioned items, this study employed Raju method. For Raju method, three-parameter logistic model was selected. Signed and unsigned area between two item characteristic curve were measured within the real ability range. An item which was detected commonly SA and UA area in Raju method was defined as a differently functioned item. As a result of this study, six items among twenty seven items of mathematics in the TIMSS 2007 were differently functioned item. Five items among those six items, were in favor of boys and one item was in favor of girls. Number, Geometric Shapes and Measures, and Applying were in favor of boys. but Data Display, Reasoning were in favor of girls. The conclusion of this study was summarized as existing differently functioned items in TIMSS 2007 and difference between favorable domain based gender. Finally, it is desirable to consider the differently functioned items by relating those item content for improving the test reliability of TIMSS 2007.

The Impact of COVID-19 on Stock Price: An Application of Event Study Method in Vietnam

  • PHUONG, Lai Cao Mai
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.5
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    • pp.523-531
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    • 2021
  • Vietnam's Oil and gas industry make a significant contribution to the Gross Domestic Product of Vietnam. The ongoing COVID-19 pandemic has hit every industry hard, but perhaps the one industry which has taken the biggest hit is the global oil and gas industry. The purpose of this article is to examine how the COVID-19 pandemic affects the share price of the Vietnam Oil and Gas industry. The event study method applied to Oil and Gas industry index data around three event days includes: (i) The date Vietnam recognized the first patient to be COVID-19 positive was January 23, 2020; (ii) The second outbreak of COVID-19 infection in the community began on March 6, 2020; (iii) The date (30/3/2020) when Vietnam announced the COVID-19 epidemic in the whole territory. This study found that the share price of the Vietnam Oil and Gas industry responded positively after the event (iii) which is manifested by the cumulative abnormal return of CAR (0; 3] = 3.8% and statistically significant at 5 %. In the study, event (ii) has the most negative and strong impact on Oil and Gas stock prices. Events (i) favor negative effects, events (iii) favor positive effects, but abnormal return change sign quickly from positive to negative after the event date and statistically significant shows the change on investors' psychology.

A Study on Wave Responses of Vertical Tension-Leg Circular Floating Bodies (연직인장계류된 원형부유체의 파랑응답에 관한 연구)

  • Lee, Kwang-Ho;Kim, Chang-Hoon;Kim, Do-Sam
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.23 no.3
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    • pp.248-257
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    • 2011
  • In the present study, we proposed a new numerical wave tank model to analyze the vertical tension-leg circular floating bodies, using a 2-D Navier-Stokes solver. An IBM(Immersed Boundary Method) capable of handling interactions between waves and moving structures with complex geometry on a standard regular Cartesian grid system is coupled to the VOF(Volume of Fluid) method for tracking the free surface. Present numerical results for the motions of the floating body were compared with existing experimental data as well as numerical results based on FAVOR(Fractional Area Volume Obstacle Representation) algorithm. For detailed examinations of the present model, the additional hydraulic experiments for floating motions and free surface transformations were conducted. Further, the versatility of the proposed numerical model was verified via the numerical and physical experiments for the general rectangular floating bodies. Numerical results were compared with experiments and good agreement was archived.

Electronic Structure Calculations for ArCO$_2\;^+$ and ArCO$_2$

  • Hwang, Woong-Lin;Lee, Yoon-Sup;Kim, Ja-Hong
    • Bulletin of the Korean Chemical Society
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    • v.9 no.3
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    • pp.153-156
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    • 1988
  • Ab initio calculations are performed for $ArCO_2^+$ and $ArCO_2$. Between the two configurations of $ArCO_2^+$ the orbital interactions and the higher order correlation calculations favor the T-shape, and their interaction energies are calculated to be approximately half the experimental values using 6-31G$^{\ast}$ basis set. In $ArCO_2$, the calculations qualitatively favor the T-structure, which is compatible with the experiment. However, the true interaction energy is obscured since it is within the BSSE limit at this basis set size and the correlation level. Addition of sp type diffuse functions increase the interaction energies by a considerable amount, but the BSSE estimated by CP method are responsible for the significant portion of the difference. The possible equilibrium structure of the $Ar^+-CO_2$ complex, where the charge is localized on Ar, is suggested as having a linear structure. The potential energy surface and the amount of charge transfer are shown to be sensitive to the type and balancing of basis set.

The Importance of One-Eletron Effects in Conformation and Protonation of Acetamides $^*$

  • Ik-Choon Lee;Geoun-Bae Rhyu
    • Bulletin of the Korean Chemical Society
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    • v.1 no.1
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    • pp.17-22
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    • 1980
  • The CNDO/2 method was used to compute relative stabilities of various configurations and conformations of acetamide, N-methylacetamide and diacetamide and their protonated forms. It was found that: (a) nonbonded interactions play important roles in determining structural preferences of the compounds, (b)$n-{\sigma}^{\ast}$ "throughbond" interactions always favor cis-protonation (relative to C-N).

A Study on the Property of Semiconductive Shield Composite through Karl Fischer Method in Power Cable (Karl Fischer를 통한 전력케이블용 반도전 Composite 특성 연구)

  • Yang, Hoon;Park, Dae-Hee
    • Proceedings of the KIEE Conference
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    • 2008.05a
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    • pp.187-188
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    • 2008
  • In this paper, we have investigated water content of semiconductive shield materials for power cables, EEA(Ethylene Ethyl Acrylate) is used polymer matrix. And filler is used CNT(Carbon Nanotube) and CB(Carbon Black). EEA, CNT and CB is favor moisture. In case of EEA, it has polyolefin resin that strong polarity combination. To research water content, experimental method used KF(Karl Fischer). KF method is Electrochemical titration based on chemical reaction. As a result, specification by KEPCO(Korea Electric Power Corporation) is lower than 800ppm. CNT and CB ratio of 80 versus 20 is best specimen that had lowest moisture content. It seem likely to increase crosslinking rate, CNT between CB.

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A Study of Azo-Hydrazone Tautomerism in 3-Phenyl-4-arylazo-5-isozaolones by $^H-NMR$ spectra of $^{15}N-labeled$ Compounds and HMO Method

  • Shawali, Ahmad S.;Salkaabi, harifia S.;Abdallah, Magda A.
    • Archives of Pharmacal Research
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    • v.14 no.3
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    • pp.237-241
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    • 1991
  • The tautomerism in 3-phenyl-4-arylazo-5-isoxazolones 1 was examined by $^1H-NMR$ spectra of $^15N-labeled$ compound and by HMO method. Both spectra data $(^1H-NMR\;and\;IR)$ and bonding energies are in support of the assignment of the hydrazone structure to such compounds. It is further shown that intermolecular and intramolecular hydrogen bondings favor the hydrazone tautomer.

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A Case Study on the Teaching Method of the "Noise" Unit (소음 단원의 교수-학습 모형 개발 및 적용에 관한 현장 연구)

  • 송호열
    • Hwankyungkyoyuk
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    • v.15 no.2
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    • pp.14-29
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    • 2002
  • The environment of the world becomes deteriorated rapidly as the result of the development of technology, the increase of the standard of living, and the growth of population. These circumstances called for environmental education in Korea, creating an environment course in the middle and high school in 1995. Despite the increasing importance of environmental education, however, the situation has not developed in its favor because of the current system of the university entrance examination. The school has failed to develop the curriculum of environmental education in the secondary education. This paper solves this problem internally in terms of the improvement of the contents, organization, teaching method (role-playing game), and teaching materials of environmental education, with a case study of the “noise” unit in 10th grade. This case study expects to change the attitude toward noise, increase the interest and knowledge in environment, and lead to responsible environmental behavior.

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Comparison of Numerical Models for Nonlinear Stream Function Wave Theory (유량함수 비선형 파랑이론의 수치모형 비교)

  • 서승남
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.6 no.4
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    • pp.353-363
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    • 1994
  • In order to give a useful guide for engineering applications on numerical models based on nonlinear stream function wave theory. collocation method and least squares method are directly compared input parameters of the revised Dean's Table (Chaplin, 1980). Two models ive both accurate and almost same results for all the cases except very long or nearly breaking waves. Overall comparison seems to favor the least squares method for general use.

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