Protograph LDPC Based Distributed Joint Source Channel Coding

该文提出一种基于原模图低密度奇偶校验(P-LDPC)码的分布式联合信源信道编译码系统方案。该方案编码端,分布式信源发送部分信息位及校验位以同时实; 现压缩及纠错功能;译码端,联合迭代信源信道译码的运用进一步发掘信源的相关性以获得额外的编码增益。此外,论文研究了所提方案在译码端未知相关性系数的; 译码算法。仿真结果表明,所提出的基于P-LDPC码的分布式联合信源信道编译码方案在外部迭代次数不大的情况可以获得较大的性能增益,并且相关性系数在; 译码端已知和未知系统性能基本相当。This paper proposes a Distributed Joint Source-Channel Coding (DJSCC); scheme using Protograph Low Density Parity Check (P-LDPC) code. In the; proposed scheme, the distributed source encoder sends some information; bits together with the parity bits to simultaneously achieve both; distributed compression and channel error correction. Iterative joint; decoding is introduced to further exploit the source correlation.; Moreover, the proposed scheme is investigated when the correlation; between sources is not known at the decoder. Simulation results indicate; that the proposed DJSCC scheme can obtain relatively large additional; coding gains at a relatively small number of global iterations, and the; performance for unknown correlated sources is almost the same as that; for known correlated sources since correlation can be estimated jointly; with the iterative decoding process.福建省自然科学基金; 国家自然科学基

终极股权结构、法律制度与股权资本成本

采用527家非金融类上市公司截面数据,运用普通最小二乘估计法实证检验终极股权结构、法律制度与股权资本成本的关系,以及法律制度和终极股权结构对股权资本成本的交互作用。研究表明:(1)国有控股的上市公司比非国有控股的上市公司具有更低的股权资本成本;(2)终极控股股东的现金流量权与公司股权资本成本呈负相关关系;(3)终极控股股东的控制权与公司股权资本成本呈正相关关系;(4)终极控股股东的现金流量权和控制权的分离度与公司股权资本成本呈正相关关系;(5)法律制度越完善的地区,对投资者保护水平越高,公司的股权资本成本越低;(6)完善的法律制度会减弱终极股权结构对股权资本成本的影响

台湾海峡真光层有机碳动力学研究──DOC大幅度的日变化

1994年8月和1995年2月在台湾海峡对dOC作定点连续观测，发现dOC日变化很大（2~4Mg/dM3），且变化的幅度有季节差异和空间差异；dOC昼夜变化的总的规律是白天比晚上高，夜晚始终处于低值；依据dOC的昼夜变化可将dOC分为dOCnEW和dOCOld两部分；d0CnEW在真光层中快速地产生、消耗、再循环；dOCOld则相对稳定，可从真光层底部输出；dOC的快速变化表明dOC的产生和被细菌消耗利用的速度都非常快.文中还尝试快速富丽叶变换（ffT）来分离引起dOC日变化的物理因子和生物因子，并依据实验结果讨论了初级生产力，微生物对dOC的利嵱茫模希檬涑錾Φ任侍狻国家教委和福建省重点课题基

Protograph-based LDPC decoder applied to magnetic recording channel

针对传统原模图低密度奇偶校验(lOW dEnSITy PArITy CHECk,ldPC)码在译码硬件实现中,由于采用随机扩展方式,导致数据拥塞和布线困难,继而产生译码延时和资源消耗的提高及吞吐量的下降问题,通过2步准循环扩展得到了适于硬件实现的码字结构,设计了一种面向磁记录信道的原模图ldPC码译码器。该译码器信息更新采用基于TdMP(TurbO dECOdIng MESSAgE PASSIng)分层译码的归一化MIn-SuM算法使得译码器具有部分并行架构;同时为了降低译码时间及功耗,给出一种低资源消耗的提前终止迭代策略。硬件实现结果表明,该译码器的译码性能十分接近相应的浮点算法,在低资源消耗的前提下,工作频率可达183.9 MHz,吞吐量为63.3 MbIT/S,并可同时适用于多种原模图ldPC码。Using random expansion algorithm,the hardware implementation of conventional protograph-based LDPC(low density parity check) decoders has difficulty with wiring and data transmission,which results in the improvement of resource consumption and decrease in throughput.In this paper,an easy-hardware-implementation quasi cyclic protographbased LDPC code is obtained by the use of a two-step lifting procedure,and we also propose a protograph-based LDPC decoder for magnetic recording channels.Utilizing the normalized Min-Sum algorithm based on the TDMP(Turbo decoding message passing) layered decoding scheme,the proposed decoder has a partially parallel architecture.Moreover,an early termination strategy is also proposed to reduce the latency and power consumption of the decoder.The proposed LDPC decoder is evaluated on a Xilinx Spartan 6 FPGA(field programmable gate array) platform and the results indicate that the proposed decoder requires low resource and can be utilized for multiple protograph-based LDPC codes.国家自然科学基金(61271241)~

Advances inthe studies onlight absorption properties of phyto-plankton

国家自然科学基金资助项目(40376031);; 国家863计划资助项目(2002AA639540);; 国家自然科学重点基金资助项目(40331004

基于潮汐表数据同化的天文潮数值预报模型及其模拟预报效果

[摘要]：潮汐表是利用长期潮汐观测结果经调和分析实现的主要港湾潮汐预报结果, 具有较高的预报 精度, 而通常的天文潮数值预报目前还难以达到潮汐表的预报精度. 本研究在建立常规天文潮数值 预报模型的基础上, 建立了基于潮汐表数据同化的天文潮数值预报模型, 并分别采用这2种模型预 报福建沿岸海域的天文潮. 其结果表明同化模型的预报结果无论是在潮时还是在潮高均明显优于 常规模型; 同化模型能显著地改善所研究的沿岸海域90个水位点中至少45个水位点的潮汐预报 结果, 而其他水位点的预报结果也有不同程度地改善.国家863 计划重大资助项目( 2006AA09A302-6

历代医家论治冻疮学术思想探析

冻疮为冬日常见病,虽多数病情轻微,但影响美观,且反复发作,因此冻疮防治研究仍具较强临床需要。本研究通过查阅、整理历代医家对冻疮的论述发现历代医家对冻疮认识全面,治法丰富,不仅外治法用药简便、剂型丰富、分阶段用药,预防亦有明显特色。研究结果不仅给冻疮临床治疗提供借鉴,且对进一步相关药物开发提供基础。全国第六批老中医药专家学术经验继承工作(No．国中医药人教发〔2017〕29号)国家中医药管理局第四批全国中医优秀人才项目(No.2017124)厦门市科技惠民计划项目(No.3502Z20174028)厦门大学医学院创新训练项目(No.2017Y0856

A preliminary study of the variation of phytoplankton absorption coefficients in the northern South China Sea

The temporal and spatial variabilities of phytoplankton absorption coefficients (a(ph)(lambda)) and their relationships with physical processes in the northern South China Sea were examined., based on in situ data collected from two cruise surveys during May 14 to 25 2001. and November 2 to 21, 2002. Significant changes in the surface water in a,h values and B/R ratios (a(ph)(440)/a(ph)(675)) were observed in May, which were caused by a phytoplankton bloom on the inner shelf stimulated by a large river plume due to heavy precipitation. This is consistent with the observed one order of magnitude elevation of chlorophyll a and a shift from a pico/nano dominated phytoplankton community to one dominated by micro-algae. Enhanced vertical mixing due to strengthened northeast monsoon in November has been observed to result in higher surface a(ph)(675) (0.002-0.006 m(-1) higher) and less pronounced subsurface maximum on the outer shelf/slope in November as compared with that in May. Measurements of a(ph) and B/R ratios from three transects in November revealed a highest surface a(ph)(675) immediately outside the mouth of the Zhujiang (Pearl) River Estuary, whereas lower a(ph)(675) and higher B/R ratios were featured in the outer shelf/slope waters, demonstrating the respective influence of the Zhujiang River plume and the oligotrophic water of the South China Sea. The difference in spectral shapes of phytoplankton absorption (measured by B/R ratios and bathochromic shifts) on these three transects infers that picoprocaryotes are the major component of the phytoplankton community on the outer shelf/slope rather than on the inner shelf. A regional tuning of the phytoplankton absorption spectral model (Carder et al., 1999) was attempted, demonstrating a greater spatial variation than temporal variation in the lead parameter a(0)(lambda). It was thus implicated that region-based parameterization of ocean color remote sensing algorithms in the northern South China Sea was mandatory.National Basic Research Program of China [2009CB421200, 2009CB421201]; National Natural Science Foundation of China [40821063]; High-Tech R&D Program of China [2006AA09A302, 2008AA09Z108

Strong southward transport events due to typhoons in the Taiwan Strait

Transport through the Taiwan Strait under the influence of five typhoons was investigated using both buoy observations and numerical model simulations during the period of 27 August to 5 October 2005. The results show that the effects of typhoons on the Taiwan Strait and its adjacent sea area caused strong southward transport events in the Taiwan Strait, which changed the direction of the Taiwan Strait northward transport temporarily. Typhoon-generated local wind stress and/or along-strait water level gradient were the direct driving factors in these southward transport events. The numerical results show that the Coriolis force made a negative contribution to these events and the contribution of the along-strait momentum gradient was insignificant.China Postdoctoral Science Foundation [20070420745]; Science Foundation of Fujian Province [2009J01223]; National High-Tech Research and Development [2006AA09A302-6

Tide-surge Interaction Intensified by the Taiwan Strait

The Taiwan Strait is a long and wide shelf-channel where the hydrodynamics is extremely complex, being characterized by strong tides, and where storm surges frequently occur during the typhoon season. Obvious oscillations due to tide-surge interaction were observed by tide gauges along the northern Fujian coast, the west bank of the Taiwan Strait, during Typhoon Dan (1999). Numerical experiments indicate that nonlinear bottom friction (described by the quadratic formula) is a major factor to predict these oscillations while the nonlinear advective terms and the shallow water effect have little contribution. It is found that the tide-surge interaction in the northern portion of the Taiwan Strait is intensified by the strait. Simulations based on simplified topographies with and without the island of Taiwan show that, in the presence of the island, the channel effect strengthens tidal currents and tends to align the major axes of tidal ellipses along the channel direction. Storm-induced currents are also strengthened by the channel. The pattern of strong tidal currents and storm induced currents along the channel direction enhances tide-surge interaction via the nonlinear bottom friction, resulting in the obvious oscillations along the northern Fujian coast.Science Foundation of Fujian Province [2009J01223]; National High-tech RD Program [2006AA09A302-6]; National Oceanographic Partnership Program [N00014-06-1-0945