• 한국멀티미디어학회논문지
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• 제25권11호
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• pp.1582-1590
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• 2022

Due to the situation of the widespread of the coronavirus, which causes the problem of lack of face image data occluded by masks at recent time, in order to solve the related problems, this paper proposes a method to generate face images with masks using a combination of generative adversarial networks and spatial transformation networks based on CNN model. The system we proposed in this paper is based on the GAN, combined with multi-scale convolution kernels to extract features at different details of the human face images, and used Wasserstein divergence as the measure of the distance between real samples and synthetic samples in order to optimize Generator performance. Experiments show that the proposed method can effectively put masks on face images with high efficiency and fast reaction time and the synthesized human face images are pretty natural and real.

• 방송과미디어
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• 제4권4호
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• pp.46-51
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• 1999

The introduction of broadcast digital television (DTV) was, at one time, seen as an opportunity to rationalise video formats. The reality is quite different with a rapid divergence as the united States' ATSC offers 18 formats to cover both standard definition (SD) and high definition (HD), and yet more are supported by Europe's DVB. At the same time multi-media is expanding both as an area for source material and for finished work. Post production needs to move away from single-format facilities as requirements for multi-format operation is already increasing. A 'format-independent' solution is described which allows efficient operation with any mix of input formats and able to output any format with high quality. Attention is given to retaining the speed, accuracy and immediacy which is a feature of today's professional facilities -even while handling the greater demands of HD. Another route, using 24 frames-per-second is also examined.

• The Journal of Asian Finance, Economics and Business
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• 제9권3호
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• pp.1-10
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• 2022

This research proposes a novel trading method based on sample entropy for the FTSE China A50 Index. The approach is used to determine the points at which the index should be bought and sold for various holding durations. The findings are then compared to three other trading strategies: buying and holding the index for the entire time period, using the Relative Strength Index (RSI), and using the Moving Average Convergence Divergence (MACD) as buying/selling signaling tools. The unique entropy trading method, which used 90-day holding periods and was called StEn(90), produced the highest cumulative return: 25.66 percent. Regular buy and hold, RSI, and MACD were all outperformed by this strategy. In fact, when applied to the same time periods, RSI and MACD had negative returns for the FTSE China A50 Index. Regular purchase and hold yielded a 6% positive return, whereas RSI yielded a 28.56 percent negative return and MACD yielded a 33.33 percent negative return.

• International Journal of Contents
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• 제4권2호
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• pp.7-12
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• 2008

In this paper, we present a real-time physical simulation model of water surfaces with a novel method to represent the water mass flow in full three dimensions. In a physical simulation model, the state of the water surfaces is represented by a set of physical values, including height, velocity, and the gradient. The evolution of the velocity field in previous works is handled by a velocity solver based on the Navier-Stokes equations, which occurs as a result of the unevenness of the velocity propagation. In this paper, we integrate the principle of the mass conservation in a fluid of equilateral density to upgrade the height field from the unevenness, which in mathematical terms can be represented by the divergence operator. Thus the model generates waves induced by horizontal velocity, offering a simulation that puts forces added in all direction into account when calculating the values for height and velocity for the next frame. Other effects such as reflection off the boundaries, and interactions with floating objects are involved in our method. The implementation of our method demonstrates to run with fast speed scalable to real-time rates even for large simulation domains. Therefore, our model is appropriate for a real-time and large scale water surface simulation into which the animator wishes to visualize the global fluid flow as a main emphasis.

• Smart Structures and Systems
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• 제17권5호
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• pp.753-771
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• 2016

This paper addresses the free and transient responses of a SDOF linear complex stiffness system by making use of the Hilbert transform and the convolution integral. Because the second-order differential equation of motion having the complex stiffness give rise to the conjugate complex eigen values, its time-domain analysis using the standard time integration scheme suffers from the numerical instability and divergence. In order to overcome this problem, the transient response of the linear complex stiffness system is obtained by the convolution integral of a green function which corresponds to the unit-impulse free vibration response of the complex system. The damped free vibration of the complex system is theoretically derived by making use of the state-space formulation and the Hilbert transform. The convolution integral is implemented by piecewise-linearly interpolating the external force and by superimposing the transient responses of discretized piecewise impulse forces. The numerical experiments are carried out to verify the proposed time-domain analysis method, and the correlation between the real and imaginary parts in the free and transient responses is also investigated.

• Structural Engineering and Mechanics
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• 제48권6호
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• pp.879-914
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• 2013

In part I of the article, formulation and characteristics of the several well-known structural geometrical nonlinear solution techniques were studied. In the present paper, the efficiencies and capabilities of residual load minimization, normal plane, updated normal plane, cylindrical arc length, work control, residual displacement minimization, generalized displacement control and modified normal flow will be evaluated. To achieve this goal, a comprehensive comparison of these solution methods will be performed. Due to limit page of the article, only the findings of 17 numerical problems, including 2-D and 3-D trusses, 2-D and 3-D frames, and shells, will be presented. Performance of the solution strategies will be considered by doing more than 12500 nonlinear analyses, and conclusions will be drawn based on the outcomes. Most of the mentioned structures have complex nonlinear behavior, including load limit and snap-back points. In this investigation, criteria like number of diverged and complete analyses, the ability of passing load limit and snap-back points, the total number of steps and analysis iterations, the analysis running time and divergence points will be examined. Numerical properties of each problem, like, maximum allowed iteration, divergence tolerance, maximum and minimum size of the load factor, load increment changes and the target point will be selected in such a way that comparison result to be highly reliable. Following this, capabilities and deficiencies of each solution technique will be surveyed in comparison with the other ones, and superior solution schemes will be introduced.

• 한국환경과학회지
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• 제21권12호
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• pp.1511-1521
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• 2012

An attempt is made to analyse characteristic features of heavy rainfalls which occur at the metropolitan area of the Korean peninsular the on- and off- Changma season. For this, two representative heavy rainfall episodes are selected; one is the on-Changma season wherein a torrential rain episode happened at Goyang city on 12 July 2006, and the other is the off-Changma season, a heavy rainfall event in Seoul on 21 September 2006. Both recorded considerable amounts of precipitation, over 250mm in a half-day, which greatly exceeded the amount expected by numerical prediction models at those times, and caused great damage to property and life in the affected area. Similarities in the characteristics of both episodes were shown by; the location of upper-level jet streak and divergence fields of the upper wind over heavy rainfall areas, significantly high equivalent potential temperatures in the low atmospheric layer due to the entrainment of hot and humid air by the low-level jet, and the existence of very dry air and cold air pool in the middle layer of the atmosphere at the peak time of the rainfall events. Among them, differences in dynamic features of the low-level jet and the position of rainfall area along the low-level jet are remarkable.

• 한국양식학회지
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• 제9권4호
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• pp.437-444
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• 1996

우리나라 해역에 서식하고 있는 농어 2형(점이 없는 계통과 점이 있는 계통)의 유전학적 분류 및 특징을 조사하기 위하여 isozyme 분석을 실시한 결과, 2형에 있어서 4개의 유전자좌의 분기가 관찰 되었으며 이중 Pt-1 유전자좌는 완전 분기되어 있는 것으로 확인되었다. 총 유전적 변이 보유량은 2형 모두 동일하였으나 점이 없는 계통은 다형 변이 유전좌의 비가 높았으며, 점이 있는 계통은 변이 유전자좌의 비가 높은 것으로 나타났다. 2형에 있어서 평균 이형 접합체율의 기대치에 차이가 나타나 점이 없는 계통과 점이 있는 계통은 유전적으로 집단구조가 다름이 확인 되었다. 2형간의 유전적 분화 정도를 나타내는 유전적 거리(D)의 값은 0.12036이었으며, 분화연도는 $6.2{\times}10^5$년전 인 것으로 추정되었다.

• Parasites, Hosts and Diseases
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• 제35권4호
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• pp.271-276
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• 1997

메타고니무스속 흡충의 형태학적인 차이점은 잘 알려져 있으나 이러한 미세한 형태학적 차이로 종을 분류할 수 있을 지에 대해서는 의문시되어 왔다. 이 연구는 비교적 유전자 염기서열이 잘 보존되어 있 어 종간 또는 strain간의 차이를 밝힐 수 있는 리보솜리보핵산 유전자 중 ITSI 유전자와 사립체 COI 유전자를 중합효소반응으로 증폭시킨 후 제한효소로 소화시켜 나타나는 밴드의 차이를 관찰하였다 요 코가와흡충 (M. yokogawai)의 피 낭유충은 삼척산 은어에서 , 미야타흡충 (Metagonim Miyata type) 은 충주산 피라미에서, 타카하시홉충 (M. tnkqhqsrii)은 충주산 붕어에서 분리하여 사용하였다. 세 종류 충체에서 얻은 ml 유전자 증폭산물은 제한효소 Rsc I, Ak I 및 Msp I에 의해 서로 다른 크기의 밴드 로 소화되었다. 세 종류 충체의 사립체 COI 유전자 증폭산물도 Rsc I과 AIu I에 의해 서로 다른 양상으로 잘라졌다. 추정 유전자 차이 (estimated genetic divergence)는 미야타홉충과 요코가와흡충이 0.034880, 요코가와흡충과 타카하시홉충이 0.018179, 미야타흡충과 타카하시흡충이 0.028098 이었다. 이 결과로 보면 미야타흡충은 별개의 종으로 볼 수 있으며,다른 충체보다 이른 시기에 진화하였음 을 알 수 있다.

• Advances in nano research
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• 제9권3호
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• pp.133-145
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• 2020

In this study, nonlinear vibrations and dynamic instabilities of a smart embedded micro shell conveying varied fluid flow and subjected to the combined electro-thermo-mechanical loadings are investigated. With the aim of designing new hydraulic sensors and actuators, the piezoelectric materials are employed for the body and the effects of applying electric field on the stability of the system as well as the induced voltage due to the dynamic behavior of the system are studied. The nonlocal piezoelasticity theory and the nonlinear cylindrical shell model in conjunction with the energy approach are utilized to mathematically modeling of the structure. The fluid flow is assumed to be isentropic, incompressible and fully develop, and for more generality of the problem both steady and time dependent flow regimes are considered. The mathematical modeling of fluid flow is also carried out based on a scalar potential function, time mean Navier-Stokes equations and the theory of slip boundary condition. Employing the modified Lagrange equations for open systems, the nonlinear coupled governing equations of motion are achieved and solved via the state space problem; forth order numerical integration and Bolotin's method. In the numerical results, a comprehensive discussion is made on the dynamical instabilities of the system (such as divergence, flutter and parametric resonance). We found that applying positive electric potential field will improve the stability of the system as an actuator or vibration amplitude controller in the micro electro mechanical systems.