低频可控震源在准噶尔盆地某三维项目中的应用

本文介绍了BV-620LF低频可控震源首次在大沙漠地区的生产施工中,通过采取合适的措施和合理的生产组织方式,实现了高效采集,并获得了较好的地震资料。这说明BV-620LF低频可控震源完全具备大沙漠区作业能力,值得在类似地区进行推广应用。

Soft-sensing Design Based on Semiclosed-loop Framework

Soft-sensing is widely used in industrial applications. The traditional soft-sensing structure is open-loop without correction mechanism. If the working condition is changed or there is unknown disturbance, the forecast result of soft-sensing model may be incorrect. In order to obtain accurate values, it is necessary to carry out online correction. In this paper, a semiclosed-loop framework (SLF) is proposed to establish a soft-sensing approach, which estimates the input variables in the next moment by a prediction model and calibrates the output variables by a compensation model. The experimental results show that the proposed method has better prediction accuracy and robustness than other open-loop models.

Bayesian Lasso for Screening Experiments

The purpose of variable selection is to identify important predictors for response variables. Although there are many varieties of variable selection methods, almost all of them have a problem of not accounting for the relationship between predictors. Therefore it would well happen that the selected subset of identified predictors leads to hard-to-interpret model consisted of only interaction terms. In design of experiments, the analysis is driven by the effect heredity principle which governs the relationship between an interaction and its corresponding main effects. In this paper, the authors extend the variable selection method the Lasso with effect heredity principle to its Bayesian version. In the example, the authors analyze the data obtained from typical screening design Plackett-Bunnan design and compare the result from the ordinary Bayesian Lasso and proposed method.

An Evaluation of South Korean Container Sea Port Development Policy

As Busan New Port has been developed with a total scale of 30 berths in 2020, the chronic problem of Busan port, a lack of port facilities, is being addressed, and there is a growing interest in regard to port development with an optimal scale. The Korean container port development under the master plan for national port development reveals a severe problem of excess supply of port facility in some ports. This paper, the authors analysed the second and the third master plan for national port development implemented in 2001 and 2011, and a revised plan in 2006, along with the amended predictions for container throughput. Furthermore, the effectiveness of the implementation of the initial plan, and the current situation of South Korea＇s main container ports of Busan, Gwangyang, Incheon, and Pyeongtaek ＆ Dangjin was examined. Through the analysis of port vitalizations, we have examined the actual problems for the prediction of container throughput. Also, this research analysed the functional difference of each port and organized the function of each one discriminatively. Therefore, identifies the problems, which arise with making the container throughput forecasts, which is a fimdamental aspect of existing port development policy, and suggest a direction for future port development by synthesizing the results of analysis.

Numerical Noise Prediction in Fluid Machinery

Numerical methods successively became important in the design and optimization of fluid machinery. However, as noise emission is considered, one can hardly find standardized prediction methods combining flow and acoustical optimization. Several numerical field methods for sound calculations have been developed. Due to the complexity of the considered flow, approaches must be chosen to avoid exhaustive computing. In this contribution the noise of a simple propeller is investigated. The configurations of the calculations comply with an existing experimental setup chosen for evaluation. The used in-house CFD solver SPARC contains an acoustic module based on Ffowcs Williams-Hawkings Acoustic Analogy. From the flow results of the time dependent Large Eddy Simulation the time dependent acoustic sources are extracted and given to the acoustic module where relevant sound pressure levels are calculated. The difficulties, which arise while proceeding from open to closed rotors and from gas to liquid are discussed.

Empirical Model for the Quantitative Prediction of Losses of Radial Fans based on CFD Calculations

In a classical layout process of a fan the quantity of losses is estimated as a sum and expressed in the overall efficiency rote However the characteristic of the pressure rise, the losses and the efficiency rate beside the design point is not known. Against this background a numerical model was developed to calculate quantitative values of occurring losses at radial fan impellers at an early stage in the design process. It allows to estimate the pressure rise and efficiency rate of a given fan geometry at and beside the design point. The physics of losses are described in literature, but obtaining quantitative values is still a challenge. As common in hydraulic theory the losses are calculated with analytic formulas supported by coefficients and efficiency rates, which have to be determined empirically. This paper shows the method how to determine the coefficients for a given radial fan. Therefore a representative radial fan with backward curved blades was designed in reference to classical design guidelines. Performance measuring was done conform to ISO 5801. The flow was calculated at 8 different operation points using CFD methods. The RANS equations are solved by using the SST-k-omega turbulence model. The flow do- main consists of one blade section including inlet channel and outflow chamber. Spatial discretization is done by a block-structured mesh of approx. 1.8 million cells. Performance data show a very good agreement between measurement and calculation.