• 제목/요약/키워드: Prediction Program

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Performance Prediction of Centrifugal Pumps using Two Zone Model (두영역모델을 사용한 원심펌프의 성능예측)

  • Choi, Young-Seok;Shim, Jae-Hyeok;Kang, Shin-Hyoung
    • 유체기계공업학회:학술대회논문집
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    • 1998.12a
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    • pp.33-41
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    • 1998
  • In this study, the performance prediction programs for centrifugal pumps are developed. To estimate the losses in the centrifugal pump impellers, two-zone model and TEIS(two elements in series) model are applied to the program. The basic concept of two zone model considers the primary zone that is an isentropic core flow and the secondary zone that is non-isentropic region at the impeller exit. The flows through two different zones mixed out at the impeller exit and the mixing process occurs with an increase in entropy, a decrease in total pressure. The level of the core flow diffusion in a impeller was calculated using TEIS(two elements in series) model. The effects of various parameters which are used in this program on the prediction of head and efficiency are discussed. The correlation curves to select the effectiveness of the primitive TEIS model were suggested according to the specific speed of the centrifugal pumps.

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Minimally Complex Problem Set for an Ab initio Protein Structure Prediction Study

  • Kim RyangGug;Choi Cha-Yong
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.9 no.5
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    • pp.414-418
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    • 2004
  • A 'minimally complex problem set' for ab initio protein Structure prediction has been proposed. As well as consisting of non-redundant and crystallographically determined high-resolution protein structures, without disulphide bonds, modified residues, unusual connectivities and heteromolecules, it is more importantly a collection of protein structures. with a high probability of being the same in the crystal form as in solution. To our knowledge, this is the first attempt at this kind of dataset. Considering the lattice constraint in crystals, and the possible flexibility in solution of crystallographically determined protein structures, our dataset is thought to be the safest starting points for an ab initio protein structure prediction study.

A Study on the Prediction and Database Program of Ship Noise (선박소음예측 및 데이터베이스 프로그램 개발)

  • 박종현;김동해
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2001.05a
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    • pp.149-154
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    • 2001
  • Ship owners are demanding quieter vessels since crews have become more sensitive to their acoustic environment. Accordingly, designers of shipyards need to respond intelligently to the challenging requirements of delivering a quiet vessel. In early design stage, to predict shipboard noise the statistical approach is preferred to other methods because of simplicity. However, since the noise characteristics of the ships vary continuously with the environments, it is necessary to update the prediction formula with data base management system. This paper describes the feature of database program with the prediction method. Database management programs with GUI, are applied to Intranet system that is accessible by any users. Statistical approach to the prediction of A-weighted noise level in ship cabins, based on multiple regression analysis, is conducted. The noise levels in ship cabins are mainly affected by the parameters of the deadweight, the type of ship, the relative location of engines and cabins, the type of deckhouse, etc. As a result of verification, the formulas ensure the accuracy of 3 ㏈ in 83 % of cabins.

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Noise Prediction of Train Using Ray Tracing Method and Statistical Energy Analysis (음선추적법과 통계적 에너지 분석법을 이용한 철도차량 실내 소음 해석)

  • Park, Hee-Jun
    • Proceedings of the KSR Conference
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    • 2010.06a
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    • pp.942-946
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    • 2010
  • As the major sources of interior noise of train at running condition are the wheel/rail contact noise, the traction motor's noise and the driving gear's noise and these noise sources are transmitted through the car body, the noises of HVAC and air duct can be ignored. But the interior noise of train at standstill condition is decided by HVAC's noise and noise from the diffuser through the air duct. the interior noise prediction of train at standstill condition should be performed considering the shape of air duct, the air velocity and noise reduction property inside the air duct. But it is hard to estimate the interior noise level by the numerical method. Therefore train maker predict the interior noise level using The commercial noise prediction program. This paper introduce the noise prediction method of the train at standstill condition using the commercial program appling the ray tracing method and statistical energy analysis.

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The Joint Frequency Function for Long-term Air Quality Prediction Models (장기 대기확산 모델용 안정도별 풍향·풍속 발생빈도 산정 기법)

  • Kim, Jeong-Soo;Choi, Doug-Il
    • Journal of Environmental Impact Assessment
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    • v.5 no.1
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    • pp.95-105
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    • 1996
  • Meteorological Joint Frequency Function required indispensably in long-term air quality prediction models were discussed for practical application in Korea. The algorithm, proposed by Turner(l964), is processed with daily solar insolation and cloudiness and height basically using Pasquill's atmospheric stability classification method. In spite of its necessity and applicability, the computer program, called STAR(STability ARray), had some significant difficulties caused from the difference in meteorological data format between that of original U.S. version and Korean's. To cope with the problems, revised STAR program for Korean users were composed of followings; applicability in any site of Korea with regard to local solar angle modification; feasibility with both of data which observed by two classes of weather service centers; and examination on output format associated with prediction models which should be used.

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Fatigue Growth Life Prediction for Collinear Multiple Surface Cracks (동일평면상에 존재하는 복수표면균열의 피로성장수명예측)

  • Lee, J.H.;Choy, Y.S.;Kim, Y.J.
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.7 s.94
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    • pp.1668-1677
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    • 1993
  • The objective of this paper is to develop a computational model for predicting the fatigue propagation of collinear multiple surface cracks under constant amplitude and variable amplitude loadings. After examining fatigue crack growth behavior for CT specimens and single surface crack specimens, empirical equations of(11) and(12) are proposed for the prediction of fatigue life in a multiple surface crack geometry. The accuracy of the proposed model is verified using a life prediction computer program. Several case studies were performed to check the accuracy of the proposed model and to verify the usefulness of the developed program. Good agreement is observed between the numerical results based on the proposed model and the published experimental data.

Noise Prediction of HRSG for Gas Turbine (복합발전용 배열회수보일러의 소음예측)

  • 남경훈;박석호;김백영;김원일
    • Journal of KSNVE
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    • v.9 no.6
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    • pp.1116-1122
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    • 1999
  • HRSG, which is one of main components of the combined cycle power plant,is composed of an inlet duct, a main body and casing, an outlet duct and a stack. It is important to design HRSG wihtin the allowable noise limit. For this purpose, it is necessary to analyze and predict the noise reduction and radiation at HRSG. In this paper, the technology for the noise prediction at each part of HRSG has been based on the empirical and field data, and also the HRSG noise prediction program has been developed. In order to verify the developed technology and program a field test is conducted. The results of noise prediction show good agreement with the measured.

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Performance Prediction of Centrifugal Pumps using a Two Zone Model (두영역모델을 사용한 원심펌프의 성능예측)

  • Choi, Young-Seok;Shim, Jae-Hyeok;Kang, Shin-Hyoung
    • The KSFM Journal of Fluid Machinery
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    • v.2 no.1 s.2
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    • pp.56-63
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    • 1999
  • In this study, the performance prediction programs for centrifugal pumps are developed. To estimate the losses in the centrifugal pump impellers, a two-zone model and TEIS(two elements in series) model are applied to the program. The basic concept of a two zone model considers the primary zone that is an isentropic core flow and the secondary zone that has a non-isentropic region at the impeller exit. The flow goes through two different zones and is mixed out at the impeller exit and the mixing process occurs with an increase in entropy, a decrease in total pressure. The level of the core flow diffusion in an impeller was calculated using TEIS(two elements in series) model. The effects of various parameters which are used in this program on the prediction of head and efficiency are discussed. The correlation curves used to select the effectiveness of the primitive TEIS model were suggested according to the specific speed of the centrifugal pumps.

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A Noise Control of a Ro-Ro Passenger Ferry (대형 Ro-Ro Ferry의 방음 설계)

  • 김동해;박종현
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2003.05a
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    • pp.738-741
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    • 2003
  • In general, the essential requirement for cruisers or car ferries is the reduction in noise to ensure high quality and comfort. Recently, the Ro-Ro Passengers Ferry (ROPAX) was built in Hyundai Heavy Industries. In order to minimize the noise levels, careful attention have to De paid by the special committee of experts from the initial design stage to the sea trial. Proper countermeasures, considering the characteristics of sources and receiver spaces, were applied from the noise prediction and various experiment results. Finally, this ship was successfully delivered with excellent noise properties. This paper describes the procedure of noise analysis, the countermeasures of noise control, and the measurement results of the sea trial. Onboard noise analysis had been carried out by statistical energy analysis program and outdoor noise prediction program based on ISO9614. The prediction results are in good agreements with the measurement results. The technology to minimize the noise levels for cruisers or car ferries has been established throughout the construction of this ship.

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Development of a Program for Consolidation Analysis Using Nonlinear Finite Strain Consolidation Theory (비선형 유한변형률 압밀이론을 이용한 압밀 해석 프로그램 개발)

  • Lee, Song;Lee, Kyu-Hwan;Jeon, Je-Sung
    • Proceedings of the Korean Geotechical Society Conference
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    • 1999.02a
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    • pp.36-47
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    • 1999
  • Terzaghi's theory of one-dimensional consolidation is restricted in its applicability to relatively thin layers and small incremental loading. Because it is assumed to infinitesimal strain and linear material function. For this reason, Gibson et al established a rigorous formulation for the one-dimensional nonlinear finite strain consolidation theory. There are some difficulties in the application of finite strain consolidation theory. The developed program consisted of several forms and modules. These forms and modules with graphic-user-interfaced format are used in analysis of consolidation practices. For the purpose of verification of developed program. the results of case study and prediction of developed program are compared. The results of comparison is fairly well with prediction and measured data. And with varying finite strain consolidation parameter, g(e) or λ(e), the sensitivity of predicted values were examined.

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