Ocean bottom seismograph （OBS） is widely used in investigating deep crustal structure, which is characterized by a large amount of data information and abundant frequency components because of its multi-component ac...Ocean bottom seismograph （OBS） is widely used in investigating deep crustal structure, which is characterized by a large amount of data information and abundant frequency components because of its multi-component acquisition. OBS is seldom used in deepwater oil and gas exploration and basin research due to the high cost. The complicated seismic wave field is caused by the complex seabed topography, basin and oil and gas structure in deepwater area, which increases the difficulty of image processing. In addition to reflection imaging, we utilize the multiple of OBS data to make accurate imaging and have achieved desirable results in a deep sea area in South China Sea in this paper. Firstly, the original P and Z components of OBS data are processed by wave field separation to obtain the upgoing wave filed and downgoing wave filed. Secondly, its image velocity filed is constructed. Finally, downgoing wave data is used to image （called mirror migration）. Compared with conventional migration, the mirror migration can clearly image the seabed and provide better illumination for shallow layer below the seafloor in the case of sparse nodes, which is proved by the migration results of theoretical and real data in this paper.展开更多
The accuracy and repeatability of the laser interferometer measurement system （LIMS） are often limited by the mirror surface error that comes from the mirror surface shape and distortion. This paper describes a new ...The accuracy and repeatability of the laser interferometer measurement system （LIMS） are often limited by the mirror surface error that comes from the mirror surface shape and distortion. This paper describes a new method to calibrate mirror map on ultraprecise movement stage （UPMS） with nanopositioning and to make a real-time compensation for the mirror surface error by using mirror map data tables with the software algorithm. Based on the mirror map test model, the factors affecting mirror map are analyzed through geometric method on the UPMS with six digrees of freedom. Dam processing methods including spline interpolation and spline offsets are used to process the raw sampling data to build mirror map tables. The linear interpolation as compensation method to make a real-time correction on the stage mirror unflatness is adopted and the correction formulas are illuminated. In this way, the measurement accuracy of the system is obviously improved from 40 nm to 5 nm.展开更多
[目的]针对传统文本替换数据增强技术所导致的扩充句对语义不对齐的问题,提出一种面向低资源神经机器翻译的源语言镜像的数据增强(data augmentation via source language mirroring,DASLM)方法.[方法]DASLM通过凯撒加密技术进行源语言...[目的]针对传统文本替换数据增强技术所导致的扩充句对语义不对齐的问题,提出一种面向低资源神经机器翻译的源语言镜像的数据增强(data augmentation via source language mirroring,DASLM)方法.[方法]DASLM通过凯撒加密技术进行源语言语句的字母级加密,增加源语言和目标语言之间的形式多样性,同时强化源语言与目标语言之间的语言不变特征;利用多语言联合训练可增强编码器提取语言不变特征的特点,用镜像语料与原始语料联合训练翻译模型.采用CCMT2023藏汉、维汉和蒙汉数据集,在Transformer模型框架下进行性能评估,并与多种主流数据增强方法进行对比.[结果]DASLM在藏汉、维汉与蒙汉3个低资源翻译任务中的BLEU值分别为24.71%、31.78%和41.67%.该方法在提升模型准确性的同时,能够在无额外模型训练的情况下达到媲美现有复杂增强方法的性能.在CCMT2024评测中取得较好的成绩.[结论]源语言镜像数据能保持与原始语料相似的语义和句法结构,DASLM方法克服了机器翻译任务中传统数据增强方法语义不对齐和译文不自然的缺陷,显著适用于低资源机器翻译.展开更多
Network attached storage (NAS) with the properties of improved scalability, simplified management, low cost and balanced price performance, is desirable for high performance storage systems applied to extensive area...Network attached storage (NAS) with the properties of improved scalability, simplified management, low cost and balanced price performance, is desirable for high performance storage systems applied to extensive areas. Unfortunately, it also has some disadvantages such as increased network workload, and inconvenience in disaster recovery. To overcome these disadvantages, we propose a channel bonding technique and provide hot backup functions in the designed NAS system, named HUSTserver. Channel bonding means merging multiple Ethernet channels into integrated one, and that the data packets can be transferred through any available network channels in a parallel mode. The hot backup function provides automatic data mirroring among servers. In this paper, we first describe the whole system prototype from a software and hardware architecture view. Then, multiple Ethernet and hot backup technologies that distinguish HUSTserver from others are discussed in detail. The findings presented demonstrate that network bandwidth can be scaled by the use of multiple commodity networks. Dual parallel channels of commodity 100 Mbps Ethernet are both necessary and sufficient to support the data rates of multiple concurrent file transfers. And the hot backup function introduced in our system provides high data accessibility.展开更多
基金supported by the National Natural Science Foundation of China (No. 41230318)the National High Technology Research and Development Program 863 (No. 2013AA092501)the Qingdao National Laboratory for Marine Science and Technology Innovation Project of Aoshan (No. 2015ASKJ03)
文摘Ocean bottom seismograph （OBS） is widely used in investigating deep crustal structure, which is characterized by a large amount of data information and abundant frequency components because of its multi-component acquisition. OBS is seldom used in deepwater oil and gas exploration and basin research due to the high cost. The complicated seismic wave field is caused by the complex seabed topography, basin and oil and gas structure in deepwater area, which increases the difficulty of image processing. In addition to reflection imaging, we utilize the multiple of OBS data to make accurate imaging and have achieved desirable results in a deep sea area in South China Sea in this paper. Firstly, the original P and Z components of OBS data are processed by wave field separation to obtain the upgoing wave filed and downgoing wave filed. Secondly, its image velocity filed is constructed. Finally, downgoing wave data is used to image （called mirror migration）. Compared with conventional migration, the mirror migration can clearly image the seabed and provide better illumination for shallow layer below the seafloor in the case of sparse nodes, which is proved by the migration results of theoretical and real data in this paper.
文摘The accuracy and repeatability of the laser interferometer measurement system （LIMS） are often limited by the mirror surface error that comes from the mirror surface shape and distortion. This paper describes a new method to calibrate mirror map on ultraprecise movement stage （UPMS） with nanopositioning and to make a real-time compensation for the mirror surface error by using mirror map data tables with the software algorithm. Based on the mirror map test model, the factors affecting mirror map are analyzed through geometric method on the UPMS with six digrees of freedom. Dam processing methods including spline interpolation and spline offsets are used to process the raw sampling data to build mirror map tables. The linear interpolation as compensation method to make a real-time correction on the stage mirror unflatness is adopted and the correction formulas are illuminated. In this way, the measurement accuracy of the system is obviously improved from 40 nm to 5 nm.
文摘[目的]针对传统文本替换数据增强技术所导致的扩充句对语义不对齐的问题,提出一种面向低资源神经机器翻译的源语言镜像的数据增强(data augmentation via source language mirroring,DASLM)方法.[方法]DASLM通过凯撒加密技术进行源语言语句的字母级加密,增加源语言和目标语言之间的形式多样性,同时强化源语言与目标语言之间的语言不变特征;利用多语言联合训练可增强编码器提取语言不变特征的特点,用镜像语料与原始语料联合训练翻译模型.采用CCMT2023藏汉、维汉和蒙汉数据集,在Transformer模型框架下进行性能评估,并与多种主流数据增强方法进行对比.[结果]DASLM在藏汉、维汉与蒙汉3个低资源翻译任务中的BLEU值分别为24.71%、31.78%和41.67%.该方法在提升模型准确性的同时,能够在无额外模型训练的情况下达到媲美现有复杂增强方法的性能.在CCMT2024评测中取得较好的成绩.[结论]源语言镜像数据能保持与原始语料相似的语义和句法结构,DASLM方法克服了机器翻译任务中传统数据增强方法语义不对齐和译文不自然的缺陷,显著适用于低资源机器翻译.
文摘Network attached storage (NAS) with the properties of improved scalability, simplified management, low cost and balanced price performance, is desirable for high performance storage systems applied to extensive areas. Unfortunately, it also has some disadvantages such as increased network workload, and inconvenience in disaster recovery. To overcome these disadvantages, we propose a channel bonding technique and provide hot backup functions in the designed NAS system, named HUSTserver. Channel bonding means merging multiple Ethernet channels into integrated one, and that the data packets can be transferred through any available network channels in a parallel mode. The hot backup function provides automatic data mirroring among servers. In this paper, we first describe the whole system prototype from a software and hardware architecture view. Then, multiple Ethernet and hot backup technologies that distinguish HUSTserver from others are discussed in detail. The findings presented demonstrate that network bandwidth can be scaled by the use of multiple commodity networks. Dual parallel channels of commodity 100 Mbps Ethernet are both necessary and sufficient to support the data rates of multiple concurrent file transfers. And the hot backup function introduced in our system provides high data accessibility.
