This work is carried out to predict the special distribution of electric field induced by multi-circuit intersecting overhead high-voltage (HV) transmission lines (TLs) within a large range without any expensive and t...This work is carried out to predict the special distribution of electric field induced by multi-circuit intersecting overhead high-voltage (HV) transmission lines (TLs) within a large range without any expensive and time-consuming computation. The two main parts of the presented methodology are 1) setting up a three-dimensional (3D) model to calculate the electric field based on combining ca- tenary equations with charge simulation method and 2) calculating the hybrid electric field excited by multi-circuit intersecting TLs using coordinate transformation and superposition technique. Examples of different TLs configurations, including a 220 kV single-circuit hori- zontally configured TLs, a 500 kV single-circuit triangularly configured TLs and a combination of the 220 kV TLs and the 550 kV TLs, are illustrated to verify the validity of this methodology. A more complicatal configurations, including a 500 kV double-circuit TLs and two 220 kV single-circuit horizontally configured TLs, are also calculated. Conclusions were drawn from the simulation: 1) The presented 3D model outperforms 2D models in describing the electric field distribution generated by practical HV TLs with sag and span. 2) Coordinate trans- formation and superposition technique considerably simplify the electric field computation for multi-circuit TLs configurations, which makes it possible to deal with complex engineering problems. 3) The electric field in the area covered by multiple intersecting overhead TLs is distorted and the hybrid electric field strength in some partial region increases so sharply that it might exceed the admissible value. 4) The configuration parameters of the TLs and the spatial configuration of multi-circuit TLs, for instance, the height of TLs, the length of span and the intersection angle of multiple circuits, influence the strength and the distribution of hybrid electric field. The influence regularities sum- marized in this paper can be referred by future TL designs to meet the electromagnetic environmental protection regulations.展开更多
By studying the variations of balloon height and of wind-ing radius in any one winding layer of ring spinning, the formula for determining the winding tension in any layer is derived, and then the overall tension vari...By studying the variations of balloon height and of wind-ing radius in any one winding layer of ring spinning, the formula for determining the winding tension in any layer is derived, and then the overall tension variation throughout all winding layers can be computed. A meth-od of measuring the winding tension is also introduced here, with the measured results agreeing with the com-puted ones, and so the reliable relationship between winding tension, speed and ring traveller weight can be thus obtained. The highest allowable spindle speed is also discussed.展开更多
This paper is mainly concerned with the wet comfort of the fine denier propylene knitted garment. The subjec-tive sensation to these propylene garments is recorded in wear trial and analyzed. The relations among the n...This paper is mainly concerned with the wet comfort of the fine denier propylene knitted garment. The subjec-tive sensation to these propylene garments is recorded in wear trial and analyzed. The relations among the normal objective test, the manikin test and the subjective wear test are discussed. The wicking height, the moisture re-sistance, the water holding ability, the moisture releas-ing and drying ability are recommended as the normal objective ways to evaluate fabric’s wet comfort. At last, some principles on designing this type of fabrics are sug-gested .展开更多
隐私集合求交(Private Set Intersection,PSI)属于隐私计算领域的特定应用问题,包括秘密共享、同态加密、不经意传输、混淆电路和Hash技术等基础知识,其兼具重要的理论意义与极强的现实应用价值。随着用户数据的隐私保护需求的日益提升,...隐私集合求交(Private Set Intersection,PSI)属于隐私计算领域的特定应用问题,包括秘密共享、同态加密、不经意传输、混淆电路和Hash技术等基础知识,其兼具重要的理论意义与极强的现实应用价值。随着用户数据的隐私保护需求的日益提升,PSI可以在满足依赖个人信息的业务的便利性的同时最大程度保护个人信息私密性需求。本文首先介绍了隐私集合求交的研究现状,其次按照底层密码技术对PSI进行分类并对比分析了它们的复杂度,对其优缺点进行对比分析,同时对比分析了基于不同密码技术的PSI的使用场景,最后指出其发展方向并得出结论。展开更多
Based on the construction method of system- atically constructed Gallager （SCG）（4, k） code, a new improved construction method of low density parity check （LDPC） code is proposed. Compared with the construction ...Based on the construction method of system- atically constructed Gallager （SCG）（4, k） code, a new improved construction method of low density parity check （LDPC） code is proposed. Compared with the construction method of SCG（4, k） codes improved before, the proposed construction method has some advantages, such as saving storage space and reducing computation complexity in the hardware implementation. And then LDPC（5929, 5624） code with 5.42% redundancy is constructed by the proposed method. The simulation results and analysis show that the constructed LDPC（5929, 5624） code has better error-correction performance, lower redundancy and lower decoding complexity than those of a classic Reed- Solomon （RS）（255, 239） code. Therefore, LDPC（5929, 5624） code, constructed by the proposed construction method on LDPC codes, can better suitable for optical transmission systems.展开更多
基金Project supported by Scientific Research Foundation of State Key Laboratory of Power Transmission Equipment ＆ System Security and New Technology （2007DA1051271 2204）, Natural Science Foundation of Chongqing Municipality （cstc201 ljjA20009）.
文摘This work is carried out to predict the special distribution of electric field induced by multi-circuit intersecting overhead high-voltage (HV) transmission lines (TLs) within a large range without any expensive and time-consuming computation. The two main parts of the presented methodology are 1) setting up a three-dimensional (3D) model to calculate the electric field based on combining ca- tenary equations with charge simulation method and 2) calculating the hybrid electric field excited by multi-circuit intersecting TLs using coordinate transformation and superposition technique. Examples of different TLs configurations, including a 220 kV single-circuit hori- zontally configured TLs, a 500 kV single-circuit triangularly configured TLs and a combination of the 220 kV TLs and the 550 kV TLs, are illustrated to verify the validity of this methodology. A more complicatal configurations, including a 500 kV double-circuit TLs and two 220 kV single-circuit horizontally configured TLs, are also calculated. Conclusions were drawn from the simulation: 1) The presented 3D model outperforms 2D models in describing the electric field distribution generated by practical HV TLs with sag and span. 2) Coordinate trans- formation and superposition technique considerably simplify the electric field computation for multi-circuit TLs configurations, which makes it possible to deal with complex engineering problems. 3) The electric field in the area covered by multiple intersecting overhead TLs is distorted and the hybrid electric field strength in some partial region increases so sharply that it might exceed the admissible value. 4) The configuration parameters of the TLs and the spatial configuration of multi-circuit TLs, for instance, the height of TLs, the length of span and the intersection angle of multiple circuits, influence the strength and the distribution of hybrid electric field. The influence regularities sum- marized in this paper can be referred by future TL designs to meet the electromagnetic environmental protection regulations.
文摘By studying the variations of balloon height and of wind-ing radius in any one winding layer of ring spinning, the formula for determining the winding tension in any layer is derived, and then the overall tension variation throughout all winding layers can be computed. A meth-od of measuring the winding tension is also introduced here, with the measured results agreeing with the com-puted ones, and so the reliable relationship between winding tension, speed and ring traveller weight can be thus obtained. The highest allowable spindle speed is also discussed.
文摘This paper is mainly concerned with the wet comfort of the fine denier propylene knitted garment. The subjec-tive sensation to these propylene garments is recorded in wear trial and analyzed. The relations among the normal objective test, the manikin test and the subjective wear test are discussed. The wicking height, the moisture re-sistance, the water holding ability, the moisture releas-ing and drying ability are recommended as the normal objective ways to evaluate fabric’s wet comfort. At last, some principles on designing this type of fabrics are sug-gested .
文摘隐私集合求交(Private Set Intersection,PSI)属于隐私计算领域的特定应用问题,包括秘密共享、同态加密、不经意传输、混淆电路和Hash技术等基础知识,其兼具重要的理论意义与极强的现实应用价值。随着用户数据的隐私保护需求的日益提升,PSI可以在满足依赖个人信息的业务的便利性的同时最大程度保护个人信息私密性需求。本文首先介绍了隐私集合求交的研究现状,其次按照底层密码技术对PSI进行分类并对比分析了它们的复杂度,对其优缺点进行对比分析,同时对比分析了基于不同密码技术的PSI的使用场景,最后指出其发展方向并得出结论。
文摘Based on the construction method of system- atically constructed Gallager （SCG）（4, k） code, a new improved construction method of low density parity check （LDPC） code is proposed. Compared with the construction method of SCG（4, k） codes improved before, the proposed construction method has some advantages, such as saving storage space and reducing computation complexity in the hardware implementation. And then LDPC（5929, 5624） code with 5.42% redundancy is constructed by the proposed method. The simulation results and analysis show that the constructed LDPC（5929, 5624） code has better error-correction performance, lower redundancy and lower decoding complexity than those of a classic Reed- Solomon （RS）（255, 239） code. Therefore, LDPC（5929, 5624） code, constructed by the proposed construction method on LDPC codes, can better suitable for optical transmission systems.
