Effects of parent acclimatization in the south of China on growth, development and thermotolerance of juvenile sea cucumbers Apostichopus japonicus

本文探讨了获得耐高温刺参苗种的可行途径并研究了亲本南方驯化对后代生长以及耐热性的影响，结果总结如下： 1.福建省刺参人工苗种繁育技术研究 为了解决限制福建省刺参养殖产业发展的关键问题—苗种生产，我们以亲本高温驯化和囊胚期浮游幼体高温应激相结合的方法摸索出一套苗种繁育工艺。适应福建省水域条件的耐高温的刺参亲本是成功的前提条件。通过对刺参进行长时间福建省驯化我们获得了一批性状优良的亲本。驯化期间，为了缓解高温对刺参的不利影响，合成了一种用于刺参夏季培育的复合维生素制剂，实际应用效果明显。通过不断尝试，我们摸索出一套成熟的苗种繁育技术，获得了大量耐高温刺参苗种。运用此技术，可在福建省进行刺参...1. Study on the artificial breeding technology of sea cucumber in the south of China In order to solve the key problem restricting the development of sea cucumber culture in the south of China, a combination method of parent thermal acclimation with heat-shock at gastrula larvae was applied to explore artificial breeding technology of this species. Adults with high thermotolerance were essential ...学位：博士后院系专业：海洋与地球学院_海洋生物学学号：201217001

书媒广告的市场憧憬与现实悖论

书媒广告一度被视为出版业的赢利蓝海,受到业界与学界的关注。但近十年来,其市场总体表现并不理想,未能形成可观的业务规模与稳定的商业模式。本文通过对从业人士的深度访谈,试图了解当前书媒广告的现实问题,探究其深层次原因。研究发现,图书作为广告载体在技术操作与商业逻辑等方面存在着若干缺陷,广告效果无法预测与及时反馈是关键问题所在

Similarity Search of Time Series with Moving Average Based Indexing

提出了基于移动均值的索引来解决子序列匹配中的"(-查询"问题;提出并证明了基于移动均值的缩距定理和缩距比关系定理,后者具有很好的"裁减"能力,可以在相似查询时淘汰大部分不符合条件的候选时间序列,从而达到快速相似查找的目的;引入了由Jagadish 等人提出的BATON*-树,并在此基础上适当修改,建立了MABI索引,极大地加快了相似查询过程;最后,在一个股票交易数据集上进行了实验,证明了MABI索引的良好性能.In this paper, a method called MABI (moving average based indexing) is proposed to effectively deal with the issue of (-search query in subsequence matching. Two important theorems, distance reduction theorem and DRR(distance reduction rate) relation theorem, are proposed here to be as the basis of MABI. DRR relation theorem has strong capability in "pruning" those unqualified candidate sequences so as to achieve of fast similarity search. Furthermore, by modifying BATON* introduced by Jagadish, et al., a multi-way balanced tree structure is introduced, to construct the index from time series, which significantly speeds up the similarity search. Extensive experiments over a stock exchange dataset show that MABI can achieve desirable performance.Supported by the National Natural Science Foundation of China under Grant No.60473051(国家自然科学基金); The National High-Tech Research and Development Plan of China under Grand Nos.2007AA01Z191, 2006AA01Z230 (国家高技术研究与发展计划(863)

Effects of parent acclimation and heat-shock at gastrula on growth and development of sea cucumber larvae

文章探讨了刺参(APOSTICHOPuS JAPOnICuS)亲本南方驯化和囊胚期幼体热应激对浮游幼体生长、发育的影响。刺参亲本分为未度夏(dA)组和已度夏(XP)组,每组设置对照组(C)和热应激组(H),在囊胚期对H组进行45MIn、26℃的高温应激,然后分别在18℃和23℃下培育至变态。结果表明,培育温度对H组和C组幼体的生长有显著影响,C组幼体在23℃下的特定生长率高于18℃,而H组正好相反。从耳状幼体第2天开始,dA组和XP组幼体的最大体长开始出现在H组,这与幼体对饵料的摄取有关。H组幼体的变态率要显著低于C组,这归因于高温应激导致的高畸形率。dA组和XP组幼体的生长、成活以及附着变态率之间差异不显著。鉴于之前研究结果,可通过下述途径获取耐高温刺参苗种:首先在囊胚期进行高温应激获取耐高温幼参,然后在南方进行幼体培育和中间养成,性成熟后进行苗种繁育,最后经过累代选育固定耐高温性状。This study investigated the effects of parent-acclimation and heat-shock at gastrula stage on growth and development of sea cucumber( Apostichopus japonicus) larvae.The adult sea cucumbers were split into two groups: DA group and XP group,each with two treatments: control( C) and heat-shock( H).Gastrula larvae of H were heated at 26 ℃ for 45 min and then reared at 18 ℃ and23 ℃ separately until metamorphosis.Results show that the specific growth rate at 23 ℃ was higher than that at 18 ℃ in the control,but the trend was opposite in heat-shock treatment.Since the 2ndday of auricularia,the maximum body length had been observed in heat-shock treatment for both DA and XP group,which was due to the ingestion of food.The setting rate of heat-shock treatment was significantly lower than that of the control due to the high rate of deformed individuals caused by heat-shock.Thus,high temperatureresistant sea cucumbers can be acquired via the following steps: first,obtain a certain number of high temperature-resistant juveniles by heat-shock at gastrula stage; then,culture these individuals in southern China until sexual maturity; finally,fix the high temperature-resistant properties by generation selection.中国博士后科学基金(2013M541862); 福建省杰出青年基金(2011J06017

Research on Materialized View Selection

定义了数据仓库领域的视图选择问题,并讨论了与该问题相关的代价模型、收益函数、代价计算、约束条件和视图索引等内容;介绍了3大类视图选择方法,即静态方法、动态方法和混合方法,以及各类方法的代表性研究成果;最后展望未来的研究方向.Definition of view selection issue in the field of data warehouses is presented, followed by the discussion of related problems, such as cost model, benefit function, cost computation, restriction condition, view index, etc. Then three categories of view selection methods, namely, static, dynamic and hybrid methods are discussed. For each method, some representative work is introduced. Finally some future trends in this area are discussed.Supported by the National Natural Science Foundation of China under Grant No.60473051 (国家自然科学基金); the National High-Tech Research and Development Plan of China under Grant Nos.2007AA01Z191, 2006AA01Z230 (国家高技术研究发展计划(863)

Change Data Capture in Real-Time Active Data Warehouses: A Survey

本文是在北京大学数据库实验室攻读博士学位期间发表的。实时主动数据仓库是数据仓库的最新发展阶段和未来发展趋势,它为企业提供了对战略决策和战术决策的双重支持.实时主动数据仓库中包含两类数据,即实时数据和非实时数据,相应地,需要两种不同类型的变化数据捕捉方法,即支持实时变化数据捕捉的方法和普通的(不支持实时的)变化数据捕捉方法.结合在该领域的研究经验,对实时主动数据仓库中可以使用的多种变化数据捕捉方法进行了系统地论述,并比较各种方法的应用条件、优点、缺点和适用场合。Real-time active data warehouse is the most recent stage in the evolution history of data warehouses．It supports both strategic decision and tactic decision，which will bring great benefits to organizations．There are two types of data existing in real-time active data warehouses，i．e．，real-time data and non-real-time data．Accordingly，change data capture methods are classified into tWO kinds，including those supporting real-time change data capture and those not supporting real-time change data capture．Based on extensive research work in this field，those change data capture methods are systematically discussed，which may meet the requirements in real-time active data warehouses．国家自然科学基金项目(60473015)；国家“863”高技术研究发展计划基金项目(2006AAl2Z217)；HP中国实验室联合项

Research on Requirement-based Real-time Data Integration in Real-time Active Data Warehouses

本文是在北京大学数据库实验室攻读博士学位期间发表的。实时数据集成是实时主动数据仓库研究领域的一个重要问题。现有的研究成果都是从技术角度出发，而并没有考虑具体的商务应用需求。而在大型商务应用中，即使采用过滤规则只捕捉感兴趣的变化数据，也会产生大量的数据集成工作，从而导致不必要的沉重系统开销，同时还很有可能出现系统响应缓慢和用户需求无法得到满足等情况。本文从应用角度出发，提出了实时主动数据仓库中面向需求的实时数据集成方法，包括被频繁请求的数据的实时集成、满足突发请求的实时数据集成和由用户决定的实时数据集成。针对不同的商务需求，采用不同的数据集成策略，可以很好地满足不同类型的应用需求。Real-time data integration is a very important aspect in the field of real-time active data warehouse. Almost all the available research work now is from a technological point of view instead of an application angle. While in the real-world business application, a large amount of real-time data integration needs to be done even with the help of change data capture technology to integrate only the interesting part of the data from the data source, which will usually lead to the deteriorated system performance and fail to satisfy the business requirement in some cases. From an application angle, we here propose three requirement-based real-time data integration methods, including: real-time integration for the frequently requested data, real-time integration for the suddenly arising requirement and user-decided real-time integration. By adopting the appropriate method for the specific application occasion, we can better satisfy the various business requirements.国家自然科学基金项目(60473015)；国家“863”高技术研究发展计划基金项目(2006AAl2Z217)；HP中国实验室联合项

Keyword Search over Relational Databases

介绍了基于关系数据库的关键词查询问题的研究背景;阐述了解决该问题的两大类方法,即基于数据图的方法和基于模式图的方法,并详细介绍了各种方法的原理以及各自的优缺点;最后展望了未来的研究方向。First, the research background of keyword search over relational databases is presented and is followed by a detailed description of two solutions to this problem, i.e., data graph based and schema graph based methods, and a discussion of the principles, advantages and disadvantages of these methods is also mentioned. Finally, some future trends in this area are discussed.Supported by the National Natural Science Foundation of China under Grant No.50604012 (国家自然科学基金); the National High-Tech Research and Development Plan of China under Grant No.2009AA01Z150 (国家高技术研究发展计划(863)

Hierarchical Color Image Segmentation Using Watershed Filling and Overlap-rate Measuring

由于分水岭方法进行图像分割时经常是在梯度图像上进行,并经常产生过分割的结果,因此为克服图像过分割问题和提高分割的准确性,提出了一种基于分水岭和重叠率衡量分层融合策略的彩色图像分割新算法——HWO。该算法首先将RGB颜色空间转化到Lab颜色空间,并根据a、b维来提取统计2维直方图,同时在直方图上运用分水岭分割方法,通过对峰进行填充来得到图像的初步分割结果;然后将与填充对应的分割区域样本与高斯分布结合起来,对图像进行高斯混合模型假设下的参数估计;最后对模型与模型间进行重叠率衡量及分层区域融合,以得到最终的图像分割结果。实验中,首先采用训练图像集对算法涉及的两个参数进行确定,然后对测试图像集的分割效果和分割时间性能进行评估,评估是以标准的人工分割图像库为基准的。实验结果表明,该算法可解决过分割问题,其评估所得分准率及分全率综合衡量系数为0.609,而人工分割综合衡量系数为0.79,同时新方法的分割时间仅为传统方法的1/3,分割速度有了较大提高。Watershed segmentation based on gradient images usually has over-segmentation result.To solve over-segmentation problem,we propose a new Hierarchical image segmentation method based on Watershed filling and Overlap-rate measuring(HWO).Firstly,we transform RGB color space to Lab and statistic the histogram according to a and b dimensions.The watershed segmentation algorithm is applied to 2D histogram and the initial segmentation result is achieved.Then,we associate the segmentation region with the Gaussian distributing,and estimate the parameter value.Finally,we measure the Overlap-rate for a hierarchical region merging and get the final result.In the experiment,the two parameters are determined.We then evaluate the segmentation performance with a standard database of human segmented natural images.Results show our method can efficiently solve over-segmentation problem,and the combined value of precision and recall measures is 0.609,while is 0.79 when the segmentation is done manually.In addition,the new method also has much less computing complexity.教育部“211”计划“985”工程-2期项目(000-X07204);; 国家高技术研究发展计划(863)项目(2006AA01Z129