The effect of irrigation water quality on unsaturated hydraulic conductivity (HC) of undisturbed soil in field was studied.Results show that within the operating soil suction range (0-1.6 KPa) of disc permeameters,the...The effect of irrigation water quality on unsaturated hydraulic conductivity (HC) of undisturbed soil in field was studied.Results show that within the operating soil suction range (0-1.6 KPa) of disc permeameters,the higher the electric conductivity (EC) of irrigation water,the higher the soil HC became.The soil HC doubled when EC increased from 0.1 to 6.0ds m^-1.High sodium-adsorption ratio(SAR) of irrigation water would have an unfavorable effect on soil HC.Soil HC decreased with the increasing of SAR,especially in the case of higher soil suction.An interaction existed between the effects of EC and SAR of irrigation water on soil HC.The HC of unsaturated soil dependent upon the macropores in surface soil decreased by one order of magnitude with 1 KPa increase of soil suction.In the study on the effect of very low soluble salt concentration (EC=0.1 ds m^-1 of irrigation water on soil HC,soil HC was found to be lowered by 30% as a consequence of blocking up of some continuous pores by the dispersed and migrated clay particles.Nonlinear successive regression analysis and significance test show that the effects of EC and SAR of irrigation water on soil HC reached the extremely significant level.展开更多
For the issue of flow control for Available Bit Rate (ABR) traffic in ATM network,a new improved Explicit Rate (ER) algorithm named Dynamic Double Threshold Congestion Indication (DDTCI) algorithm is presented based o...For the issue of flow control for Available Bit Rate (ABR) traffic in ATM network,a new improved Explicit Rate (ER) algorithm named Dynamic Double Threshold Congestion Indication (DDTCI) algorithm is presented based on the Explicit Forward Congestion Indication (EFCI) Current Cell Rate (CCR) algorithm and Relative Rate (RR) algorithm. Different from the early ER algorithm, both the high-level and the low-level threshold is dynamically changing according to the state of the bottleneck node. We determinate the congestion state with the information of the two dynamic threshold, and control the cell rate of the source by feed back mechanism. Except for the well performance in both link utilization and fairness in distribution of available bandwidth, the improved algorithm can alleviate the fluctuation of sending rate dramatically. The mechanism is modeled by a fluid model, and the useful expressions are derived.Simulation results show up our conclusion.展开更多
Speech coding techniques have been studied not truly to reduce the complexity and bit rate but also to improve the sound quality. CELP type vocoder, used as standard, supports the great stead quality even low bit rate...Speech coding techniques have been studied not truly to reduce the complexity and bit rate but also to improve the sound quality. CELP type vocoder, used as standard, supports the great stead quality even low bit rate. In this paper, the preprocessing of input speech to reduce the bit rate is different from the conventional vocoder. Different kinds of parameter are used for the preprocessing compared with the other parameters to t＇md the more appropriate parameter for the vocoder. The Parameters are used to synthesize the speech not to encode or decode for coding technique so we proposed the simple algorithm not to have the influence on the processing time or the computation time. The parameters in the preprocessing step are speaking rate, duration, and PSOLA technique.展开更多
When designing vehicle suspension systems, compromises are usually made when setting the range of values for spring stiffness and damping constant. Suspension parameters are set depending on the operational requiremen...When designing vehicle suspension systems, compromises are usually made when setting the range of values for spring stiffness and damping constant. Suspension parameters are set depending on the operational requirements of the market. Passenger car for example, would require high quality damping while off road vehicle requires high spring stiffness setting. A quarter vehicle suspension model has been used to study the suspension transmissibility in handling and ride at various frequency ratios. The results obtained show that as the frequency ratio increases, transmissibility for handling reduces with increasing suspension stiffness and increases as the damping constant is increased. On the other hand, transmissibility for ride deteriorate as the spring constant is increased but approaches the ideal as the damping constant is increased. The dynamic magnification of the sprung masses reduces while that of the unsprung masses improves as the frequency ratio is increased.展开更多
This paper provides empirical evidence on audit quality in Kazakhstan as measured by audit tenure and the frequency of issuing modified opinions. In addition, an overview of audit institutions of Kazakhstan and an ana...This paper provides empirical evidence on audit quality in Kazakhstan as measured by audit tenure and the frequency of issuing modified opinions. In addition, an overview of audit institutions of Kazakhstan and an analysis of the current audit market for public companies are offered. This paper also sheds light upon the potential independence problems resulting in low audit quality and current barriers to audit researches in Kazakhstan. Consistent with the findings of extant researches on audit quality and the general perceptions of investors, two hypotheses were developed, i.e., the audits performed by Big 4 audit firms in Kazakhstan also have higher quality than non-Big 4 audit firms in terms of audit tenure and the frequency of issuing modified opinions. The result confirms the hypothesis that Big 4 audit firms provide higher audit quality than smaller local firms in association with audit tenure instead of in relation to the frequency of issuing modified opinions. The result indicates that Big 4 audit firms may not be as independent as they will be in a highly litigious market. Therefore, an independent inspection should be regularly implemented according to the audit law, and the inspection report should be publicized by Chamber of Auditors （COA）1. If this is not practical due to the lack of qualified inspectors, a peer review may be an altemative to implement the quality control policy immediately. To the author＇s best knowledge, this is the first audit quality research in countries of the Commonwealth of Independence States （CIS）.展开更多
To meet the requirement of high-quality transmission of videos captured by unmanned aerial vehicles （UAV） with low bandwidth, a novel rate control （RC） scheme based on region-of-interest （ROI） is proposed. First...To meet the requirement of high-quality transmission of videos captured by unmanned aerial vehicles （UAV） with low bandwidth, a novel rate control （RC） scheme based on region-of-interest （ROI） is proposed. First, the ROI information is sent to the encoder with the latest high efficient video coding （HEVC） standard to generate an ROI map. Then, by using the ROI map, bit allocation methods are developed at frame level and large coding unit （LCU） level, to avoid inaccurate bit allocation produced by camera movement. At last, by using a better robustness R-2 model, the quantization parameter （QP） for each LCU is calculated. The experimental results show that the proposed RC method can get a lower bitrate error and a higher quality for reconstructed video by choosing appropriate pixel weight on the HEVC platform.展开更多
With the proliferation of energy storage and power applications, electric vehicles particularly, solid-state batteries are considered as one of the most promising strategies to address the ever-increasing safety conce...With the proliferation of energy storage and power applications, electric vehicles particularly, solid-state batteries are considered as one of the most promising strategies to address the ever-increasing safety concern and high energy demand of power devices. Here, we demonstrate the Al4B2O9 nanorods-modified poly(ethylene oxide) (PEO)-based solid polymer electrolyte (ASPE) with high ionic conductivity, wide electrochemical window, decent mechanical property and nonflammable performance. Specifically, because of the longer-range ordered Li+ transfer channels conducted by the interaction between Al4B2O9 nanorods and PEO, the optimal ASPE (ASPE-1) shows excellent ionic conductivity of 4.35×10^−1 and 3.1×10^−1 S cm^−1 at 30 and 60℃, respectively. It also has good electrochemical stability at 60℃ with a decomposition voltage of 5.1 V. Besides, the assembled LiFePO4//Li cells show good cycling performance, delivering 155 mA h g−1 after 300 cycles at 1 C under 60℃, and present excellent low temperature adaptability, retaining over 125 mA h g^−1 after 90 cycles at 0.2 C under 30℃. These results verify that the addition of Al4B2O9 nanorods can effectively promote the integrated performance of solid polymer electrolyte.展开更多
文摘The effect of irrigation water quality on unsaturated hydraulic conductivity (HC) of undisturbed soil in field was studied.Results show that within the operating soil suction range (0-1.6 KPa) of disc permeameters,the higher the electric conductivity (EC) of irrigation water,the higher the soil HC became.The soil HC doubled when EC increased from 0.1 to 6.0ds m^-1.High sodium-adsorption ratio(SAR) of irrigation water would have an unfavorable effect on soil HC.Soil HC decreased with the increasing of SAR,especially in the case of higher soil suction.An interaction existed between the effects of EC and SAR of irrigation water on soil HC.The HC of unsaturated soil dependent upon the macropores in surface soil decreased by one order of magnitude with 1 KPa increase of soil suction.In the study on the effect of very low soluble salt concentration (EC=0.1 ds m^-1 of irrigation water on soil HC,soil HC was found to be lowered by 30% as a consequence of blocking up of some continuous pores by the dispersed and migrated clay particles.Nonlinear successive regression analysis and significance test show that the effects of EC and SAR of irrigation water on soil HC reached the extremely significant level.
文摘For the issue of flow control for Available Bit Rate (ABR) traffic in ATM network,a new improved Explicit Rate (ER) algorithm named Dynamic Double Threshold Congestion Indication (DDTCI) algorithm is presented based on the Explicit Forward Congestion Indication (EFCI) Current Cell Rate (CCR) algorithm and Relative Rate (RR) algorithm. Different from the early ER algorithm, both the high-level and the low-level threshold is dynamically changing according to the state of the bottleneck node. We determinate the congestion state with the information of the two dynamic threshold, and control the cell rate of the source by feed back mechanism. Except for the well performance in both link utilization and fairness in distribution of available bandwidth, the improved algorithm can alleviate the fluctuation of sending rate dramatically. The mechanism is modeled by a fluid model, and the useful expressions are derived.Simulation results show up our conclusion.
基金supported by the Brain Korea 21 Project in 2010,and the MKE(The Ministry of Knowledge Economy,Korea)the ITRC(Information Technology Research Center)support program(NIPA-2010-(C1090-1021-0010))
文摘Speech coding techniques have been studied not truly to reduce the complexity and bit rate but also to improve the sound quality. CELP type vocoder, used as standard, supports the great stead quality even low bit rate. In this paper, the preprocessing of input speech to reduce the bit rate is different from the conventional vocoder. Different kinds of parameter are used for the preprocessing compared with the other parameters to t＇md the more appropriate parameter for the vocoder. The Parameters are used to synthesize the speech not to encode or decode for coding technique so we proposed the simple algorithm not to have the influence on the processing time or the computation time. The parameters in the preprocessing step are speaking rate, duration, and PSOLA technique.
文摘When designing vehicle suspension systems, compromises are usually made when setting the range of values for spring stiffness and damping constant. Suspension parameters are set depending on the operational requirements of the market. Passenger car for example, would require high quality damping while off road vehicle requires high spring stiffness setting. A quarter vehicle suspension model has been used to study the suspension transmissibility in handling and ride at various frequency ratios. The results obtained show that as the frequency ratio increases, transmissibility for handling reduces with increasing suspension stiffness and increases as the damping constant is increased. On the other hand, transmissibility for ride deteriorate as the spring constant is increased but approaches the ideal as the damping constant is increased. The dynamic magnification of the sprung masses reduces while that of the unsprung masses improves as the frequency ratio is increased.
文摘This paper provides empirical evidence on audit quality in Kazakhstan as measured by audit tenure and the frequency of issuing modified opinions. In addition, an overview of audit institutions of Kazakhstan and an analysis of the current audit market for public companies are offered. This paper also sheds light upon the potential independence problems resulting in low audit quality and current barriers to audit researches in Kazakhstan. Consistent with the findings of extant researches on audit quality and the general perceptions of investors, two hypotheses were developed, i.e., the audits performed by Big 4 audit firms in Kazakhstan also have higher quality than non-Big 4 audit firms in terms of audit tenure and the frequency of issuing modified opinions. The result confirms the hypothesis that Big 4 audit firms provide higher audit quality than smaller local firms in association with audit tenure instead of in relation to the frequency of issuing modified opinions. The result indicates that Big 4 audit firms may not be as independent as they will be in a highly litigious market. Therefore, an independent inspection should be regularly implemented according to the audit law, and the inspection report should be publicized by Chamber of Auditors （COA）1. If this is not practical due to the lack of qualified inspectors, a peer review may be an altemative to implement the quality control policy immediately. To the author＇s best knowledge, this is the first audit quality research in countries of the Commonwealth of Independence States （CIS）.
文摘To meet the requirement of high-quality transmission of videos captured by unmanned aerial vehicles （UAV） with low bandwidth, a novel rate control （RC） scheme based on region-of-interest （ROI） is proposed. First, the ROI information is sent to the encoder with the latest high efficient video coding （HEVC） standard to generate an ROI map. Then, by using the ROI map, bit allocation methods are developed at frame level and large coding unit （LCU） level, to avoid inaccurate bit allocation produced by camera movement. At last, by using a better robustness R-2 model, the quantization parameter （QP） for each LCU is calculated. The experimental results show that the proposed RC method can get a lower bitrate error and a higher quality for reconstructed video by choosing appropriate pixel weight on the HEVC platform.
基金financially supported by the National Natural Science Foundation of China (51804344)the Huxiang Youth Talent Support Program (2019RS2002)+2 种基金the Innovation and Entrepreneurship Project of Hunan Province,China (2018GK5026)the Innovation-Driven Project of Central South University (2020CX027)Guangdong Yang Fan Plan for Postdoctor Program
文摘With the proliferation of energy storage and power applications, electric vehicles particularly, solid-state batteries are considered as one of the most promising strategies to address the ever-increasing safety concern and high energy demand of power devices. Here, we demonstrate the Al4B2O9 nanorods-modified poly(ethylene oxide) (PEO)-based solid polymer electrolyte (ASPE) with high ionic conductivity, wide electrochemical window, decent mechanical property and nonflammable performance. Specifically, because of the longer-range ordered Li+ transfer channels conducted by the interaction between Al4B2O9 nanorods and PEO, the optimal ASPE (ASPE-1) shows excellent ionic conductivity of 4.35×10^−1 and 3.1×10^−1 S cm^−1 at 30 and 60℃, respectively. It also has good electrochemical stability at 60℃ with a decomposition voltage of 5.1 V. Besides, the assembled LiFePO4//Li cells show good cycling performance, delivering 155 mA h g−1 after 300 cycles at 1 C under 60℃, and present excellent low temperature adaptability, retaining over 125 mA h g^−1 after 90 cycles at 0.2 C under 30℃. These results verify that the addition of Al4B2O9 nanorods can effectively promote the integrated performance of solid polymer electrolyte.
