• Title/Summary/Keyword: Computer Simulation Program

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A simplified algorithm for conceptual estimation of the material quantities of rubble-mound breakwaters

  • Sadeghi, Kabir;Nouban, Fatemeh
    • Ocean Systems Engineering
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    • v.10 no.1
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    • pp.111-129
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    • 2020
  • A simplified algorithm is proposed for fast estimation of the material quantities required for the construction of rubble-mound breakwaters. The proposed algorithm is able to employ only the data available at feasibility study phase such as the maximum draught of the design ship selected to transport the cargos to the harbor despite, because at the feasibility phase, information for the planned harbor is likely to be very limited. A linear-constant waterdepth model together with a proposed section configuration for the breakwaters, which is customary for harbors, is considered to calculate the quantity of materials. The numerical simulation of the wave characteristics has been verified using the recorded wave data collected by a buoy installed near the Neka harbor in Caspian Sea waters. A case study has been also applied to four harbors to validate the proposed algorithm. The estimated weights using the proposed linear-constant and multi-linear waterdepth models were compared using the bathymetry maps and layouts of these harbors. A computer program, written in QBasic language, has been developed to simulate the wave characteristics and to estimate the material quantities needed to construct a rubble-mound breakwater. The obtained results show that taking into account the acceptable accuracies normally applied to the feasibility study and conceptual design phases, the proposed algorithm is sufficiently accurate and highly effective for the conceptual estimation of materials' quantities of breakwaters in the feasibility study phase of harbor projects.

A Study of Photoshop Retouching Technique for Beauty Make-up (뷰티 메이크업을 위한 포토샵 리터칭 기법 연구)

  • Kwon, Hyun-Ah
    • The Research Journal of the Costume Culture
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    • v.14 no.6
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    • pp.932-944
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    • 2006
  • With supplied computers and the development of information and communication thropugh the Internet, the space of personal home pages in potal sites has been filled with photos taken by digital cameras, and 'the introduction of privacy' done in the personal home pages has become a general trend in society. As the use of Photoshop, available to edit and modify digital photos, in this social atmosphere, has grown general, they have shown their interest in the retouching technique of Photoshop. Computer graphics, marked based on the treatment of a variety of information into pictures or a technology to mark it, recently various application methods have been found in make-up. Especially, Adobe Photoshop, used to edit and modify images, is a sofetware program proper to perform beauty make-up in correcting and creating images in an effective way. The purpose of this study is to express each factor in Adobe Photoshop CS2 about the beauty make-up. As a result, I can say, the process that digital image is retouched by Adobe Photoshop CS is similar work to beauty make-up. The process of Photoshop retouching can be used as the materials for educating of make-up and as the materials for presentation of beauty make-up trend. And also we can serve the simulation to the customer before real make-up. Therefore, this study is for the effective performance of diverse beauty makeup integrating retouch technique with Photoshop CS.

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Modeling of the Environmental Behavior of Tritium Around the Nuclear Power Plants

  • Park, Heui-Joo;Lee, Hansoo;Kang, Hee-Suk;Park, Yong-Ho;Lee, Chang-Woo
    • Nuclear Engineering and Technology
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    • v.34 no.3
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    • pp.242-249
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    • 2002
  • The relationship between the tritium release rate from the nuclear power plant and tritium concentration in the environment around the Kori site was modeled. The tritium concentration in the atmosphere was calculated by multiplying the release rates and $\chi$/Q values, and the d3V deposition rate at each sector according to the direction and the distance was obtained using a dry deposition velocity. The area around Kori site was divided into 6 zones according to the deposition rate. The six zones were divided into 14 compartments for the numerical simulation. Transfer coefficients between the compartments were derived using site characterization data. Source terms were calculated from the dry deposition rates. Tritium concentration in surface soil water and groundwater was calculated based upon a compartment model. The semi-analytical solution of the compartment model was obtained with a computer program, AMBER. The results showed that most of tritium deposited onto the land released into the atmosphere and the sea. Also, the estimated concentration in the top soil agreed well to that measured. Using the model, tritium concentration was predicted in the case that the tritium release rates were doubled.

Optimal Windows Transmittance by Energy Performance Analysis and Subjective Evaluation in office building (에너지성능분석 및 감성평가에 의한 오피스 창호의 적정 투과율 선정)

  • Kim, Byoung-Soo;Kim, Jung-Shin;Yim, Oh-Yon
    • Journal of the Korean Solar Energy Society
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    • v.24 no.3
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    • pp.73-83
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    • 2004
  • The purpose of this study is to select the optimal transmittance rate of windows in office buildings through subjective evaluation and energy performance analysis(computer simulation program ; DOE 2.1E). The results are as follows ; 1) In the subjective evaluation experiment, minimum transmittance of the glass is GE 30% and LT 70%, but the optimal transmittance rate is concluded in $40%\sim60%$. 2) As a result of the energy performance analysis, it is desirable for the building of consumptive with mainly air-conditioning to make transmittance as 40-60%. 3) Comparing foreign study on minimum and optimal transmittance rate is $25%\sim38%$, the minimum transmittance of this study is almost the same. But for the optimal transmittance rate, 20% more is needed for KOREAN.

A Study on the Bandwidth Improvement of the Microstrip Antenna for Mobile Communications (이동통신용 마이크로스트립 안테나의 대역폭 개선에 관한 연구)

  • 김대중;문명호;김갑기;이종악
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.9 no.1
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    • pp.8-15
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    • 1998
  • In this paper, to improve the bandwidth of microstrip antenna, we discussed parasitic patch structure coupled capacitively at radiating slot. To reduce the overal size of antenna,$\lambda$/4 short structure is accepted instead of $\lambda$/2 patch. Since ground plane is reduced, backward radiation is occurred. The characteristics of the designed antenna is evaluated, based on the transmission line model and the aperture analysis method. And by computer program the radiation pattern and return loss are evaluated. As simulation results, backward radiation is -15 dB. Bandwidth of constructed antenna is 167 MHz at the resonant frequency of 2.45 GHz, which is very broad, compared to conventional microstrip antennas. Therefore the proposed antenna will be suitable for very wide bandwidth communications.

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A Numerical Study on the Short-term Dispersion of Toxic Gaseous and Solid Pollutant in an Open Atmosphere : Chemical Species, Temperature, Relative Velocity (고-기상 독성오염물질 단기 대기확산에 관한 수치해석적 연구 : 화학종, 온도, 상대속도)

  • 나혜령;이은주;장동순;서영태
    • Journal of the Korean Society of Safety
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    • v.10 no.3
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    • pp.68-80
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    • 1995
  • A series of parametric calculations have been performed in order to investigate the short-term and short-range plume and puff behavior of toxic gaseous and solid pollutant dispersion in an open atmosphere. The simulation is made by the use of the computer program developed by this laboratory, in which a control-volume based finite-difference method is used together with the SIMPLEC algorithm for the resolution of the pressure-velocity coupling appeared In Wavier-Stokes equation. The Reynolds stresses are solved by the standard two-equation k-$\varepsilon$ model modified for buoyancy together with the RNG(Renormalization Group) k-$\varepsilon$ model. The major parameters considered in this calculation are pollutant gas density and temperature, the relative velocity of pollutants to that of the surrounding atmospheric air, and particulate size and density together with the height released. The flow field is typically characterized by the formation of a strong recirculation region for the case of the low density gases such as $CH_4$ and air due to the strong buoyancy, while the flow is simply declining pattern toward the downstream ground for the case of heavy molecule like the $CH_2C1_2$and $CCl_4$, even for the high temperature, $200^{\circ}C$. The effect of gas temperature and velocity on the flow field together with the particle trajectory are presented and discussed in detail. In general, the results are physically acceptable and consistent.

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An analysis on the network performance for VoD services using multicast (멀티캐스트를 이용한 VoD 서비스망의 성능 분석)

  • 백남균;정수환;민병준
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.6A
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    • pp.918-926
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    • 2000
  • A huge storage and broad bandwidth are required to provide subscribers with VoD services. Hence, there is a huge amount of cost in establishing networks for VoD services. To determine how to reduce the cost, a number of studies involving such as distributed server systems, multicasting, program caching, stream sharing, are currently in progress. In this paper, a request criterion for multicast service and the ratio of required bandwidth for unicast to multicast are generated. The effect of multicast service on network bandwidth, server bandwidth, and buffer size was analyzed and validated through computer simulation. The results of this study could be applied to efficient designing networks for VoD services.

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Application of Fuzzy PI Control Algorithm as Stator Power Controller of a Double-Fed Induction Machine in Wind Power Generation Systems

  • Chung, Gyo-Bum;Choi, Jae-Ho
    • Journal of Power Electronics
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    • v.9 no.1
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    • pp.109-116
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    • 2009
  • This paper addresses the output control of a utility-connected double-fed induction machine (DFIM) for wind power generation systems (WPGS). DFIM has a back-to-back converter to control outputs of DFIM driven by the wind turbine for WPGS. To supply commercially the power of WPGS to the grid without any problems related to power quality, the real and reactive powers (PQ) at the stator side of DFIM are strictly controlled at the required level, which in this paper is realized with the Fuzzy PI controller based on the field orientation control. For the Sinusoidal Pulse Width Modulation (SPWM) converter connected to the rotor side of DFIG to maintain the controllability of PQ at the state side of DFIM, the DC voltage of the DC link capacitor is also controlled at a certain level with the conventional Proportion-Integral (PI) controller of the real power. In addition, the power quality at the grid connected to the rotor side of DFIM through the back-to-back converter is maintained in a certain level with a PI controller of the reactive power. The controllers for the PQ at the stator side of DFIM, the DC link voltage of the back-to-back inverter and the reactive power at the grid connected to the rotor side of DFIM are designed and simulated in the PSIM program, of which the result verifies the performance of the proposed controllers.

A New Method for Evaluating Load Carrying Capacity with respect to Traffic loads (통행차량에 의한 내하력 평가기법 연구)

  • Koo, Bong-Kuen;Han, Sang-Hoon;Shin, Jae-In;Lee, Sang-Soon
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.5 no.3
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    • pp.115-122
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    • 2001
  • Bridge load rating calculations provide a basis for determining the load carrying capacity of bridges. Load rating requires engineering judgement in determining a rating value that is applicable to maintaining the safe use of the bridge and arriving at posting and permit decisions. Load testing is an effective means in calculating the rating value of bridge. In Korea, load carrying capacity of bridge is modified by response modification factor that is determined from comparisons of measured values and analysis results. This paper presents the development of a method for determining the response the modification factor, using traffic loads. The proposed method is based on the results of computer simulations of traffic action effects. The simulation program generates random traffic actions for defined traffic conditions and determines the frequency distribution of maximum traffic action effects. A comparison between the proposed method and the present method shows good agreement in estimating the modified load carrying capacity of bridges.

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The structure analysis of $Y_1Ba_2Cu_3O_x$ high Tc superconductor based on rietveld method (리트벨트 해석법을 이용한 $Y_1Ba_2Cu_3O_x$ 고온 초전도체의 구조분석)

  • 채기병;소대화
    • Electrical & Electronic Materials
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    • v.8 no.6
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    • pp.780-786
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    • 1995
  • For the execution of RIETAN program adopting Rietveld Analysis Method, the sample superconductor is made according to the solid state synthesis method at 920.deg. C for 24hrs, and was examined for the optimization of parameters needed to analyze Rietveld method with the input of the measured pattern data after measuring the pattern resulted from the X-ray diffraction. It was proven that the lattice constant of the superconductor which was consisted of Pmmm orthorhombic crystal structure in the analyzed space group correspond to the presented theoretical lattice constant a=3.8887(8).angs., b=3.8238(4).angs., c=11.7079.angs.. Therefore, it was examined and confin-ned that the R factor, which was compensated after analyzing the structure of superconductor resulted from this experimented data with the computer simulation, was refined to $R_{wp}$=8.83[%], $R_{P}$=6.47[%], $R_{I}$=10.08[%], $R_{F}$=7.19[%], $R_{E}$=3.76[%]. On the basis of these experimental data, the significant parameter such as the scale factor(S) and the zero point shift(Z) and FWHM value(U,V,W) were optimized as follows; S=2.0827E-3, Z=0.2146, U=4.2761E-2, V=1.7983E-2, and W=2.6768E-2.2.2.2.2.2.

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