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Credit Card Fraud Detection on Original European Credit Card Holder Dataset Using Ensemble Machine Learning Technique

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Journal of Cyber Security 2023年第1期5卷 33-46页

作者： yih bing chu Zhi Min Lim Bryan Keane Ping Hao Kong Ahmed Rafat Elkilany Osama Hisham Abusetta Department of Electrical and Electronic Engineering FETBEUCSI UniversityKuala Lumpur56000Malaysia

The proliferation of digital payment methods facilitated by various online platforms and applications has led to a surge in financial fraud,particularly in credit card *** technologies such as machine learning have been widely employed to enhance the early detection and prevention of losses arising frompotentially fraudulent ***,a prevalent approach in existing literature involves the use of extensive data sampling and feature selection algorithms as a precursor to subsequent *** sampling techniques can significantly reduce computational time,the resulting dataset relies on generated data and the accuracy of the pre-processing machine learning models *** datasets often lack true representativeness of realworld data,potentially introducing secondary issues that affect the precision of the *** instance,undersampling may result in the loss of critical information,while over-sampling can lead to overfitting machine learning *** this paper,we proposed a classification study of credit card fraud using fundamental machine learning models without the application of any sampling techniques on all the features present in the original *** results indicate that Support Vector Machine(SVM)consistently achieves classification performance exceeding 90%across various evaluation *** discovery serves as a valuable reference for future research,encouraging comparative studies on original dataset without the reliance on sampling ***,we explore hybrid machine learning techniques,such as ensemble learning constructed based on SVM,K-Nearest Neighbor(KNN)and decision tree,highlighting their potential advancements in the *** study demonstrates that the proposed machine learning models yield promising results,suggesting that pre-processing the dataset with sampling algorithm or additional machine learning technique may not always be *** research contributes to the fi

关键词： Machine learning credit card fraud ensemble learning non-sampled dataset hybrid AI models European credit card holder

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Theoretical Analysis of A Buoyant Jet Interacting with Small Amplitude Waves

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China Ocean Engineering 2009年第1期23卷 73-84页

作者： Ying-Pin LIN Hung-chu HSU Yang-yih CHEN Department of Marine Environment and Engineering National Sun Yat-Sen Uaivershy Kaohsiung 804 China Tainan Hydraulics Laboratory Research Center of Ocean Environment and Technology National Cheng Kung University Tainan 701 China

A new theoretical solution is presented here for the dynamic characteristics of a buoyant jet due to opposing small amplitude waves. The conservation equations of mass, tangential moment^n and vertical momentum are solved by the integral method which encompasses the Gaussian profiles of velocity and density. The action of waves is incorporated into the equations of motion as an external force and a new exact solution is obtained to predict the trajectory, velocity distribution and boundary thickness of the buoyant jet over an arbitrary lateral cross section. It is found that the velocity along the centerline is inversely proportional to the ratio of the momentum of the wave to the buoyant jet. The averaged bound- ary width varies with the fluctuation of the boundary width, the distance from the orifice and the velocity correction function. Owing to the motion of waves, the fluctuation of the boundary width is proportional to the wave steepness.

关键词： buoyant jet small amplitude waves radiation stress jet trajectory

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Theoretical and Experimental Study of Breaking Wave on Sloping Bottoms

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China Ocean Engineering 2013年第6期27卷 737-750页

作者： YANG Kuei-Sen CHEN Yang-yih LI Meng-Syue HSU Hung-chu Department of Marine Environment and Engineering National Sun Yat-Sen University International Wave Dynamics Research Center National Cheng Kung University Tainan Hydraulics Laboratory National Cheng Kung University

This paper studies the continuous evolution of breaking wave for the surface water waves propagating on a sloping beach. A Lagrangian asymptotic solution is derived. According to the solution coupled with the wave breaking criteria and the equations of water particles motion, the wave deformation and the continuous wave breaking processes for the progressive water waves propagating on a sloping bottom can be derived. A series of experiments are also conducted to compare with the theoretical solution. The results show that the present solution can reasonably describe the plunging or spilling wave breaking phenomenon.

关键词： Eulerian Lagrangian waves breaking plunging spilling

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Particle Trajectories in Nonlinear Water Wave on Uniform Current

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China Ocean Engineering 2008年第4期22卷 611-621页

作者： Hung-chu HSU Yang-yih CHEN Chia-Yan CHENG Wen-Jer TSENG Tainan Hydraulics Laboratory National Cheng Kung University Department of Marine Environment and Engineering National Sun Yat-Sen University Coastal and Offshore Resources Research Center Fisheries Research Institute Department of Civil Engineering Cheng Shiu University

The study in this paper is focusing on trajectories of particles in the irrotational progressive water waves coexisting with uniform current. The parametric equations of particle trajectories over a range of levels in a Lagrangian type of description are developed analytically via the Euler-Lagrange transformation. The Lagrangian wave period of particle motion differing from the Eulerian wave period and the mass transport can also be obtained directly. The third-order solution of particle trajectory exhibits that they do not move in closed orbital motion but represent a net movement that decreases exponentially with the water depth. Uniform current is found to have significant effect on the trajectories and drift velocity of gravity waves. Overall, the influence of increased uniform current is to increase the relative horizontal distance traveled by a particle, as well as the magnitude of the time-averaged drift velocity on the free surface. For adverse current cases, a reverse behavior is found. The obtained third-order solutions satisfy the irrotational condition contrasted to the Gerstner waves and are verified by reducing to those of two-dimensional gravity waves in Lagrangian coordinates.

关键词： wave current Lagrangian Euler- Lagrange transformation particle trajectory

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Interactions of nonlinear gravity waves and uniform current in Lagrangian system

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Acta Oceanologica Sinica 2009年第1期28卷 89-98页

作者： HSU Hung-chu CHEN Yang-yih LI Meng-Syue TSENG Wen-Jer Tainan Hydraulics Laboratory National Cheng Kung University Department of Marine Environment and Engineering National Sun Yat-Sen University Department of Civil Engineering Cheng Shiu University

The particle trajectory on a weakly nonlinear progressive surface wave obliquely interacting with a uniform current is studied by using an Euler-Lagrange *** third-order asymptotic solution is a periodic bounded function of Lagrangian labels and time,which imply that the entire solution is *** explicit parametric solution highlights the trajectory of a water particle and mass transport associated with a particle displacement can now be obtained directly in Lagrangian *** angular frequency and Lagrangian mean level of the particle motion in Lagrangian form differ from those of the *** variations in the water particle orbits resulting from the oblique interaction with a steady uniform current of different magnitudes are also investigated.

关键词： Lagrangian particle trajectory nonlinear water wave current drift velocity

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Inhibitory activities of microalgal extracts against Epstein-Barr virus DNA release from lymphoblastoid cells

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2011年第5期12卷 335-345页

作者： yih-yih KOK Wan-Loy chu Siew-Moi PHANG Shar Mariam MOHAMED Rakesh NAIDU Pey-Jiun LAI Shui-Nyuk LING Joon-Wah MAK Patricia Kim-Chooi LIM Pauline BALRAJ Alan Soo-Beng KHOO Division of Human Biology International Medical University Institute of Biological Sciences Faculty of Scienceand Institute of Ocean and Earth Sciences(IOES)University of Malaya Faculty of Medicine University of Malaya School of Medicine and Health Sciences Monash University Molecular Pathology Unit Institute for Medical ResearchJalan Pahang

This study aimed to assess the inhibitory activities of methanol extracts from the microalgae Ankistrodesmus convolutus,Synechococcus elongatus,and Spirulina platensis against Epstein-Barr virus(EBV) in three Burkitt's lymphoma(BL) cell lines,namely Akata,B95-8,and *** antiviral activity was assessed by quantifying the cell-free EBV DNA using real-time polymerase chain reaction(PCR) *** methanol extracts from Ankistrodesmus convolutus and Synechococcus elongatus displayed low cytotoxicity and potent effect in re-ducing cell-free EBV DNA(EC5028 000).After fractionation by column chromatography,the fraction from Synechococcus elongatus(SEF1) reduced the cell-free EBV DNA most effectively(EC50=2.9 μg/ml,therapeutic index>69).Upon further fractionation by high performance liquid chromatography(HPLC),the sub-fraction SEF1'a was most active in reducing the cell-free EBV DNA(EC50=1.38 μg/ml,therapeutic index>14.5).This study suggests that microalgae could be a potential source of antiviral compounds that can be used against EBV.

关键词： Microalgae Ankistrodesmus convolutus Synechococcus elongatus Spirulina platensis Lymphoblastoid cells Epstein-Barr virus(EBV)

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非旋转性自由表面重力驻波的Euler与Lagrange方法解间的转换

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物理学报 2009年第6期58卷 3637-3654页

作者：陈阳益许弘莒国立中山大学海洋环境及工程学系国立成功大学水工试验所

对于等深水中的非旋转性重力驻波流场,本文用Euler与Lagrange两种方法求得其至三阶的解,根据同一粒流体质点在相同时间与位置处其流速值为唯一与质量守恒及在自由表面水位的Euler形式解与Lagrange形式解相同等特性,来推导其间互可转换.... 详细信息

对于等深水中的非旋转性重力驻波流场,本文用Euler与Lagrange两种方法求得其至三阶的解,根据同一粒流体质点在相同时间与位置处其流速值为唯一与质量守恒及在自由表面水位的Euler形式解与Lagrange形式解相同等特性,来推导其间互可转换.由一系列连续的Taylor级数展开,在考虑波动场中各流体质点的运动轨迹与运动周期条件下,将已知的Euler解转换成完全未知的Lagrange形式解.接着再将所得的Lagrange解转换成对应的Euler形式,均可得到完全相同的结果.由此可得知,在考虑波动场各流体质点运动的真实性下,对于非旋转性的重力驻波流场而言,此两种描述方法所得之解是互通可转换的.并证实了流场中所有流体质点的运动周期是完全相同的,且恰等于自由表面波形的脉动周期.

关键词：重力驻波 Euler与Lagrange解间的转换质点运动轨迹

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Monitoring and Assessment of Oyster and Barnacle Larvae Settlement in an Oyster Farm in Western Taiwan

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Natural Resources 2020年第3期11卷 112-126页

作者： yih-Tsong Ueng Yi-Kuang Wang chun-Wen Tsao Yin Chang Shu-chu Tung Jung-Ting Hsu Department of Environmental Engineering Kun-Shan University Tainan Taiwan Department of Ecology and Environmental Resource National University of Tainan Tainan Taiwan Tainan Hydraulics Laboratory National Cheng Kung University Tainan Taiwan

The Portuguese oyster (Crassostrea angulata) is an important fishery resource in Taiwan. This study investigated oyster cultures at two locations along the coast of Taisi Township from March 2012 to July 2014. The average recruitment density, measured once every two weeks, of the oyster larvae was 256.4 ± 236.6 individuals/shell (N = 62) at site A and 118.5 ± 140.2 individuals/shell (N = 39) at site B. The average adherence density of the barnacle larvae was 187.1 ± 251.2 individuals/shell (N = 60) at site A and 60.9 ± 112.5 individuals/shell (N = 37) at site B. In Taiwan, C. angulata?spawned all year. The primary spawning season was from March to September. The primary of adherence spawning season of barnacles was from March to October. Rainfall was the major factor that influenced oyster C. angulata?and barnacle settlement, the eigenvalue of PC1 was 1.83 and could explain 61.0%. There are two main culturing seasons that move oyster larvae from coast of Taisi to farms in other places: from March to May and from August to September. Although the oyster larvae are more abundant in spring, fishermen prefer harvesting the larvae in autumn to avoid the typhoon season (July-September).

关键词： Correlation Influence Rainfall Recruitment Spat

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Numerical Simulation of an Aortic Flow Based on a HLLC Type Incompressible Flow Solver

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Communications in Computational Physics 2009年第1期5卷 142-162页

作者： Yang-Yao Niu Chih-Hung Chang Wen-yih I.Tseng Hsu-Hsia Peng Hsi-Yu Yu Department of Mechanical Engineering Chung-Hua UniversityHsin-Chu30067 Taiwan National Taiwan University Hospital No.7Chung-Shan South RoadTaipeiTaiwan

In this study,a three-dimensional artificial compressibility solver based on the average-state Harten-Lax-van Leer-Contact(HLLC)[13]type Riemann solution is first proposed and developed to solve the time-dependent incompressible flow *** implement unsteady flow calculations,a dual time stepping strategy including the LU decomposition method is used in the pseudo-time iteration and the second-order accurate backward difference is adopted to discretize the unsteady flow *** a third-order accurate HLLC numerical flux is derived for approximating the inviscid *** verify numerical accuracy,flows over a lid-driven cavity and an oscillating flat plate are chosen as the benchmark *** addition,the current solver is extended to solve blood flows in a realistic human aorta measured from MRI(Magnetic Resonance Imaging).The simulation geometry was derived from a three-dimensional reconstruction of a series of two-dimensional slices obtained in *** results demonstrate wall stresses were highly dynamic,but were generally high along the outer wall in the vicinity of the branches and low along the inner wall,particularly in the descending *** maximum wall stress distribution is presented on the aortic arch in the *** addition,extensive counter-clockwise secondary flows and three-dimensional helical vortex influenced considerably by the presence of vessel contraction,torsion and the branches were shown in the descending aorta in the late systole and early diastolic cycles.

关键词： HLLC Riemann solver incompressible flow aortic flow fluid-structure interaction

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击中月球火箭的月面击中点分佈问题

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南京大学学报(自然科学版) 1964年第4期 481-493页

作者：易照华朱耀鑫

本文以平面和空間的双二体問題为基础,研究了几种类型的击中月球火箭的軌道在击中月球时同月面交点的分布問題。得到了几种不同初始速度能垂直击中,傾斜击中以及切向击中月球的軌道在月球作用范圍边界上的进口范圍。然后得出这些軌道在... 详细信息

本文以平面和空間的双二体問題为基础,研究了几种类型的击中月球火箭的軌道在击中月球时同月面交点的分布問題。得到了几种不同初始速度能垂直击中,傾斜击中以及切向击中月球的軌道在月球作用范圍边界上的进口范圍。然后得出这些軌道在月面上击中点的分布情况;从而得出不同初始速度的軌道在月面上击中的禁区。从計算結果可看出:禁区大小主要同初始发射速度有关,速度愈大則禁区也愈大;禁区位置对上升軌道而言,在月球背面的后部(同月球运动反方向的部份),对下降軌道而言,在月球正面的后部;因此,用上升軌道也可以击中月球背面的一部份(前部),用适当的初始速度和軌道类型(上升或下降),可以击中月面上任何一点。

关键词：进口限制月球火箭初始速度双曲月面

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