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Underwater Image Enhancement Based on the Dark Channel Prior and Attenuation Compensation

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Journal of Ocean University of China 2017年第5期16卷 757-765页

作者： GUO Qingwen XUE Lulu tang ruichun GUO Lingrui College of Information Science and Engineering Ocean University of China Qingdao 266100 P. R. China College of Oceanic and Atmospheric Sciences Ocean University of China Qingdao 266100 P. R. China

Aimed at the two problems of underwater imaging, fog effect and color cast, an Improved Segmentation Dark Channel Prior(ISDCP) defogging method is proposed to solve the fog effects caused by physical properties of water. Due to mass refraction of light in the process of underwater imaging, fog effects would lead to image blurring. And color cast is closely related to different degree of attenuation while light with different wavelengths is traveling in water. The proposed method here integrates the ISDCP and quantitative histogram stretching techniques into the image enhancement procedure. Firstly, the threshold value is set during the refinement process of the transmission maps to identify the original mismatching, and to conduct the differentiated defogging process further. Secondly, a method of judging the propagating distance of light is adopted to get the attenuation degree of energy during the propagation underwater. Finally, the image histogram is stretched quantitatively in Red-Green-Blue channel respectively according to the degree of attenuation in each color channel. The proposed method ISDCP can reduce the computational complexity and improve the efficiency in terms of defogging effect to meet the real-time requirements. Qualitative and quantitative comparison for several different underwater scenes reveals that the proposed method can significantly improve the visibility compared with previous methods.

关键词： histogram underwater visibility scene attenuation foreground segmentation refinement PSNR camera

Matched Field Localization Based on CS-MUSIC Algorithm

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Journal of Ocean University of China 2016年第2期15卷 254-260页

作者： GUO Shuangle tang ruichun PENG Linhui JI Xiaopeng College of Information Science and Engineering Ocean University of China College of Information Engineering Binzhou University

The problem caused by shortness or excessiveness of snapshots and by coherent sources in underwater acoustic positioning is considered.A matched field localization algorithm based on CS-MUSIC(Compressive Sensing Multiple Signal Classification) is proposed based on the sparse mathematical model of the underwater *** signal matrix is calculated through the SVD(Singular Value Decomposition) of the observation *** observation matrix in the sparse mathematical model is replaced by the signal matrix,and a new concise sparse mathematical model is obtained,which means not only the scale of the localization problem but also the noise level is reduced;then the new sparse mathematical model is solved by the CS-MUSIC algorithm which is a combination of CS(Compressive Sensing) method and MUSIC(Multiple Signal Classification) *** algorithm proposed in this paper can overcome effectively the difficulties caused by correlated sources and shortness of snapshots,and it can also reduce the time complexity and noise level of the localization problem by using the SVD of the observation matrix when the number of snapshots is large,which will be proved in this paper.

关键词： matched field processing compressed sensing CS MUSIC

L2-LBMT:A Layered Load Balance Routing Protocol for Underwater Multimedia Data Transmission

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Journal of Ocean University of China 2017年第6期16卷 1018-1026页

作者： LV Ze tang ruichun TAO Ye SUN Xin XU Xiaowei College of Information Science and Engineering Ocean University of China Department of Information Technology Qingdao University of Science and Technology

Providing highly efficient underwater transmission of mass multimedia data is challenging due to the particularities of the underwater environment. Although there are many schemes proposed to optimize the underwater acoustic network communication protocols, from physical layer, data link layer, network layer to transport layer, the existing routing protocols for underwater wireless sensor network(UWSN) still cannot well deal with the problems in transmitting multimedia data because of the difficulties involved in high energy consumption, low transmission reliability or high transmission delay. It prevents us from applying underwater multimedia data to real-time monitoring of marine environment in practical application, especially in emergency search, rescue operation and military field. Therefore, the inefficient transmission of marine multimedia data has become a serious problem that needs to be solved urgently. In this paper, A Layered Load Balance Routing Protocol(L2-LBMT) is proposed for underwater multimedia data transmission. In L2-LBMT, we use layered and load-balance Ad Hoc Network to transmit data, and adopt segmented data reliable transfer(SDRT) protocol to improve the data transport reliability. And a 3-node variant of tornado(3-VT) code is also combined with the Ad Hoc Network to transmit little emergency data more quickly. The simulation results show that the proposed protocol can balance energy consumption of each node, effectively prolong the network lifetime and reduce transmission delay of marine multimedia data.

关键词： underwater wireless multicast multimedia data transmission load balance

Optimal tracking control for nonlinear large-scale systems with persistent disturbances

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控制理论与应用（英文版） 2010年第4期8卷 515-520页

作者： ruichun tang Xianmin LU Yili ZHAI Cunqun GONG College of Information Science and Engineering Ocean University of China Qingdao Shandong 266100 China Hisense TransTech Co. Ltd. Qingdao Shandong 266101 China Qing Dao Haier Electronic Ltd. Qingdao Shandong 266101 China

This paper studies the optimal control with zero steady-state error problem for nonlinear large-scale systems affected by external persistent *** nonlinear large-scale system is transformed into N nonlinear subsystems with interconnect *** on the internal model principle,a disturbance compensator is constructed such that the ith subsystem with external persistent disturbances is transformed into an augmented subsystem without *** to the sensitivity approach,the optimal tracking control law for the ith nonlinear subsystem can be *** optimal tracking control law for the nonlinear large-scale systems can be obtained.A numerical simulation shows that the method is effective.

关键词： Nonlinear systems Large-scale systems Persistent disturbances Optimal tracking control Sensitivity approach

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基于IA-64的虚拟接口结构设计

清华大学学报（自然科学版） 2006年第4期46卷 576-579页

作者：杨丰都志辉唐瑞春清华大学计算机科学与技术系北京100084

针对IA-64平台地址空间和数据空间的特点,该文给出一种简单有效的地址转换与数据表示方法,在此基础上提出可以有效保持虚拟接口结构(v irtua l in terfacearch itecture,V IA)各层抽象描述与具体实现相一致的设计方案。在自主研制的V I... 详细信息

针对IA-64平台地址空间和数据空间的特点,该文给出一种简单有效的地址转换与数据表示方法,在此基础上提出可以有效保持虚拟接口结构(v irtua l in terfacearch itecture,V IA)各层抽象描述与具体实现相一致的设计方案。在自主研制的V IA通信硬件基础上,实现了一个软硬件有机结合的实例THV IA 64。测试结果表明THV IA 64不仅可以稳定运行,而且具有很高的通信性能,8 B延迟为9μs,最大带宽为119 M B/s。对比数据表明V IA在IA-64平台上可以展示出更好的性能。

关键词：虚拟接口结构(VIA) 用户层通信机群 IA-64

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用户层通信网络性能测试方法

清华大学学报（自然科学版） 2005年第7期45卷 977-980页

作者：朱子玉李三立都志辉唐瑞春清华大学计算机科学与技术系北京100084

为测试用户层通信系统的细粒度通信指标,设计了一种性能测试方法。该方法通过分析用户层通信系统的系统结构和通信过程,得出各通信步骤的通信延迟情况,并使用pingpong通信程序作为性能测试基准程序。通信过程中每个步骤的时间消耗数值... 详细信息

为测试用户层通信系统的细粒度通信指标,设计了一种性能测试方法。该方法通过分析用户层通信系统的系统结构和通信过程,得出各通信步骤的通信延迟情况,并使用pingpong通信程序作为性能测试基准程序。通信过程中每个步骤的时间消耗数值可根据测试结果推导出来。测试结果表明:该测试方法简单有效;和常用的LogP测试方法相比,该测试方法得出的细粒度通信系统性能指标更实用,并能够为提高网络的通信性能和使用效率提供具有强有力说服性的依据。

关键词：设计与性能分析用户层网络性能测试