Korea Electric Power Corporation in charge of the power IT project "Development of Prototype for Advanced Substation Automation System based on the Digital Control Technology", is performing the verification of perf...Korea Electric Power Corporation in charge of the power IT project "Development of Prototype for Advanced Substation Automation System based on the Digital Control Technology", is performing the verification of performance of the substation automation system based on IEC 61850. In order to verify a transformer protective lED that might be operating in substation automation system, the new standardized document and procedures are required in the aspect of the utility like KEPCO. But there is nothing to describe systematically how to verify IEC 6 1850 based lED in the system environment except an individual IED testing way. This paper will present the substation automation system based ways and procedures to verify the protective function of the IED using UML (Unified Modeling Language).展开更多
Design, development, and testing of LPRE(Liquid Propellant Rocket Engine) are difficult and expensive tasks. Prior to full-scale design, it is indispensable to optimize important parameters at sub-scale. Propellants f...Design, development, and testing of LPRE(Liquid Propellant Rocket Engine) are difficult and expensive tasks. Prior to full-scale design, it is indispensable to optimize important parameters at sub-scale. Propellants flow rates are low for a sub-scale or laboratory scale combustion chambers. It is hard to satisfy chamber cooling and chill feed lines quickly with low flow rates of propellants. This paper proposes a detailed procedure for testing of a laboratory scale semi-cryogenic combustion chamber. Many tests were conducted with a small scale adjustable length combustion chamber. The injection head of the chamber was interchangeable. Liquid-liquid pressure swirl injector and like impinging injectors were used with two different injection heads. Liquid oxygen and kerosene were used as oxidizer and fuel, respectively. Oxidizer to fuel mixing ratio was 0.29-0.45 and the total propellant mass flow rate was 0.06-0.1 kg/s. Problems were faced during testing, including, explosion in the combustion chamber, fuel injector blockage, unstable combustion, incomplete chilling and blockage of cooling water channel, etc. A detailed procedure is designed on the basis of the lessons learned which was experimentally proved.展开更多
This paper discusses the shortcomings of the traditional Coulomb shear criterion and the direct shear-box testing method used for clayey soil and presents a modified shear criterion that considers the elasto-plastic b...This paper discusses the shortcomings of the traditional Coulomb shear criterion and the direct shear-box testing method used for clayey soil and presents a modified shear criterion that considers the elasto-plastic behavior of cohesive soil. This modified approach involves direct shear testing under constant volume, a method that has been developed by the author. A modified ring shear apparatus and the theory behind the shear criterion and its implication for slope stability analysis are then discussed and the results of investigated tuffitic clayey sediments are presented. The results show that the presented new shear criterion does not consider the cohesion as material constant, but rather it depends on the void ratio. In this case, the stress state and the consolidation status and thus the elasto-plastic behavior of the clayey soil are considered.展开更多
Using a set of measuring system installed on a testing vehicle, 15 criterion numbers, which describe the details of vehicle′s driving pattern and emission characteristic on real road condition of Tianjin, are obtaine...Using a set of measuring system installed on a testing vehicle, 15 criterion numbers, which describe the details of vehicle′s driving pattern and emission characteristic on real road condition of Tianjin, are obtained from a large quantity of raw data. The results show that the characteristic of driving pattern in Tianjin is very different from that of ECE-15 and FTP-75. That is to say, neither of these two emission testing procedures is suitable in China. A new driving cycle is developed which is accordance with the driving pattern of Tianjin.This cycle can be used to evaluate the emission levels of vehicles under real-road condition in laboratory, and can be recommended as a testing procedure used in China.展开更多
Sand production is,a challenging issue in petroleum industry,mainly associated with weak unconsolidated formations.A novel testing procedure and a new apparatus were developed to conduct an integrated experiment of di...Sand production is,a challenging issue in petroleum industry,mainly associated with weak unconsolidated formations.A novel testing procedure and a new apparatus were developed to conduct an integrated experiment of diagenesis,perforation and sand production on a single large cylindrical artificial sandstone specimen,where solid and fluid pressures can be independently controlled such that realistic reservoir historical conditions can be well simulated in the laboratory.Fluid injection can be performed in both radial and vertical directions,where both single-and two-phase flows can be implemented for study of sand production behaviors at different reservoir’s maturity stages.The equipment consists of an intensive instrumentation system to monitor pressures,displacements and material states continuously.The produced sand particles were filtered and monitored in real-time for the study of time-dependent phenomena.The experimental results showed similar patterns to that observed in the field and provided valuable insight for the development of prediction methods for sand production of similar materials.展开更多
The paper presents and discusses theoretical bases and methodology of development of two- and three-dimensional analytical and optical isodynes. Atten- tion is given to the theoretical admissibility of the major compo...The paper presents and discusses theoretical bases and methodology of development of two- and three-dimensional analytical and optical isodynes. Atten- tion is given to the theoretical admissibility of the major components of the physical and mathematical models which are taken as the theoretical basis of the isodynes, and of the related analytical and experimental procedures of stress analysis. Efficiency and reliability of the nondestructive isodyne stress analysis are discussed.展开更多
With increasing demand for nonrenewable resources,energy conservation is critical.Efficiency gains allow more work to be performed while maintaining or even decreasing the energy expended in the process.Reducing the e...With increasing demand for nonrenewable resources,energy conservation is critical.Efficiency gains allow more work to be performed while maintaining or even decreasing the energy expended in the process.Reducing the energy consumed by a system results in favorable economic and environmental impact.An apparatus has been developed to measure hydraulic fluid efficiency in a stationary application.The system can be used to develop more efficient fluids,leading to increased work output or decreased energy consumption.展开更多
This paper illustrates students' test anxiety attributable to test itself from four aspects of testing procedure — planning, preparing, administrating, and scoring. It is the test anxiety that impedes effective a...This paper illustrates students' test anxiety attributable to test itself from four aspects of testing procedure — planning, preparing, administrating, and scoring. It is the test anxiety that impedes effective and successful testing performance of students and further causes measurement error. All educators endeavor to eliminate measurement error and expect no biased results or decisions based on students' observed scores. Therefore, suggestions to solve such problems are provided here.展开更多
文摘Korea Electric Power Corporation in charge of the power IT project "Development of Prototype for Advanced Substation Automation System based on the Digital Control Technology", is performing the verification of performance of the substation automation system based on IEC 61850. In order to verify a transformer protective lED that might be operating in substation automation system, the new standardized document and procedures are required in the aspect of the utility like KEPCO. But there is nothing to describe systematically how to verify IEC 6 1850 based lED in the system environment except an individual IED testing way. This paper will present the substation automation system based ways and procedures to verify the protective function of the IED using UML (Unified Modeling Language).
文摘Design, development, and testing of LPRE(Liquid Propellant Rocket Engine) are difficult and expensive tasks. Prior to full-scale design, it is indispensable to optimize important parameters at sub-scale. Propellants flow rates are low for a sub-scale or laboratory scale combustion chambers. It is hard to satisfy chamber cooling and chill feed lines quickly with low flow rates of propellants. This paper proposes a detailed procedure for testing of a laboratory scale semi-cryogenic combustion chamber. Many tests were conducted with a small scale adjustable length combustion chamber. The injection head of the chamber was interchangeable. Liquid-liquid pressure swirl injector and like impinging injectors were used with two different injection heads. Liquid oxygen and kerosene were used as oxidizer and fuel, respectively. Oxidizer to fuel mixing ratio was 0.29-0.45 and the total propellant mass flow rate was 0.06-0.1 kg/s. Problems were faced during testing, including, explosion in the combustion chamber, fuel injector blockage, unstable combustion, incomplete chilling and blockage of cooling water channel, etc. A detailed procedure is designed on the basis of the lessons learned which was experimentally proved.
文摘This paper discusses the shortcomings of the traditional Coulomb shear criterion and the direct shear-box testing method used for clayey soil and presents a modified shear criterion that considers the elasto-plastic behavior of cohesive soil. This modified approach involves direct shear testing under constant volume, a method that has been developed by the author. A modified ring shear apparatus and the theory behind the shear criterion and its implication for slope stability analysis are then discussed and the results of investigated tuffitic clayey sediments are presented. The results show that the presented new shear criterion does not consider the cohesion as material constant, but rather it depends on the void ratio. In this case, the stress state and the consolidation status and thus the elasto-plastic behavior of the clayey soil are considered.
文摘Using a set of measuring system installed on a testing vehicle, 15 criterion numbers, which describe the details of vehicle′s driving pattern and emission characteristic on real road condition of Tianjin, are obtained from a large quantity of raw data. The results show that the characteristic of driving pattern in Tianjin is very different from that of ECE-15 and FTP-75. That is to say, neither of these two emission testing procedures is suitable in China. A new driving cycle is developed which is accordance with the driving pattern of Tianjin.This cycle can be used to evaluate the emission levels of vehicles under real-road condition in laboratory, and can be recommended as a testing procedure used in China.
基金The authors acknowledge the financial support from Nazarbayev University(Grant No.SOE2015004)Ministry of Education and Science of the Republic of Kazakhstan(Grant No.AP08052762).
文摘Sand production is,a challenging issue in petroleum industry,mainly associated with weak unconsolidated formations.A novel testing procedure and a new apparatus were developed to conduct an integrated experiment of diagenesis,perforation and sand production on a single large cylindrical artificial sandstone specimen,where solid and fluid pressures can be independently controlled such that realistic reservoir historical conditions can be well simulated in the laboratory.Fluid injection can be performed in both radial and vertical directions,where both single-and two-phase flows can be implemented for study of sand production behaviors at different reservoir’s maturity stages.The equipment consists of an intensive instrumentation system to monitor pressures,displacements and material states continuously.The produced sand particles were filtered and monitored in real-time for the study of time-dependent phenomena.The experimental results showed similar patterns to that observed in the field and provided valuable insight for the development of prediction methods for sand production of similar materials.
文摘The paper presents and discusses theoretical bases and methodology of development of two- and three-dimensional analytical and optical isodynes. Atten- tion is given to the theoretical admissibility of the major components of the physical and mathematical models which are taken as the theoretical basis of the isodynes, and of the related analytical and experimental procedures of stress analysis. Efficiency and reliability of the nondestructive isodyne stress analysis are discussed.
文摘With increasing demand for nonrenewable resources,energy conservation is critical.Efficiency gains allow more work to be performed while maintaining or even decreasing the energy expended in the process.Reducing the energy consumed by a system results in favorable economic and environmental impact.An apparatus has been developed to measure hydraulic fluid efficiency in a stationary application.The system can be used to develop more efficient fluids,leading to increased work output or decreased energy consumption.
文摘This paper illustrates students' test anxiety attributable to test itself from four aspects of testing procedure — planning, preparing, administrating, and scoring. It is the test anxiety that impedes effective and successful testing performance of students and further causes measurement error. All educators endeavor to eliminate measurement error and expect no biased results or decisions based on students' observed scores. Therefore, suggestions to solve such problems are provided here.