雅婷0302
最近在刷MIT ,记录下笔记。 可持久化数据结构就是能存储、查询数据的历史版本的数据结构。 可持久化数据结构简介 MIT 很赞!!可惜没video。 Making Data Structures Persistent 太长没看 总结了下大致包括如下领域应用: 并发事务的原子性(便于Rollback)、隔离性。 同上。 便于实现diff,rollback可持久化数据结构最初设计出来的目的是为了在高维查询中降维,把其中一个维度当做时间,用可持久化数据结构处理效率更高 可以看下MIT 老师的介绍。 这种思想在高维处理中很常见,比如求二维range sum query时候,把其中一个维度当时间、拿来做扫描线也是这种降维思路(见《算法竞赛进阶指南》): 可持久化数据结构简介 自己轮一个.net可持久化库 Persistent Data Structures 下面有讨论use case 中文翻译见 可持久化数据结构 Functional Go: 持久化数据结构简介 这部分可以看视频 把链式数据结构的模型叫pointer machine model。对于基于pointer machine model的数据结构,有没有通用的方法将他们改造成persistent? note see video see O(1)写,读时对于每个点都要执行O(logm)的查询。假设一次查询要读v个点,时间复杂度O(vlogm) 所以对写友好,对读不友好 看到这里有个问题:每个点的history放hashmap里不就行了?读时也只需要O(1)的查找 但这样做的话,hashmap不支持ceil操作,因此要支持ceil没办法只能用有序结构、log级别查询 (这里的假设是有个全局时间戳,而不是每个key对应一个自己的自增时间戳) 个人理解,想做可持久化key/value Map的话即可按这种方法,每个key对应的entry存放所有历史值,这也可以看成是邻接表。 说白了就是写时分裂节点,从root开始分裂到要写的点。将所有version的root存到字典里上面两个要么对写不好,要么对读不好,能否兼得? 难以置信,说白了就是给path copying方法中每个node加一个log cache,最后算出来的写时amortized time complexity就是O(1)了。 What about non-tree data structures? 平衡树怎么处理? 平衡树要旋转,想想就感觉很难改造成持久化。课件讲的很粗没懂。 算法竞赛中常用的可持久化平衡树一般就是 可持久化无旋转 Treap ,省去了旋转可持久化的复杂。 a. fat nodes 每个点存的log从version queue变成version tree,查询每个点时要从树中找到最近祖先 b. path copying 没区别 c. modification box 怎么找根节点? i. pointer per version,可能多个pointer指向一个root ii.存root tree,查询时先找最近祖先 怎么修改old version i. 修改时放box,满了就分裂出来一个新节点 但这样有问题:分裂出来的还是满的,如果整条链都是满的,每次修改复制全部,下次修改还得复制全部。而且这样还不好存root,比如最右边图,代表0的root有俩 ii. 修改时放box,满了就分裂出来一个新节点,但分裂时自动apply有用的log、丢弃没用的log What about non-tree data structures? 有讲,分裂成两个节点,log分成两部分,新节点拿一个子树的log,新节点apply log直到自己的子树,每部分丢弃自己用不到的。 讲了 太复杂没听懂。 网上关于可持久化数据结构的优质资料都是算法竞赛的,因此收集总结了下竞赛常用的。看了下基本都是partial persistent,有的是fully persistent,都没用到modification box技术。 和可持久化线段树类似的方法,基于path copy实现partial persistence。 问题是每个点在拷贝时都要复制O(R)个指针,插入的时间复杂度为O(len*R) 查询时先从字典(数组/哈希表)里找到指定version的root,然后访问,O(len) 在竞赛中常用的是可持久化01字典树,比如xor问题,见 ,没看懂 算法竞赛中常用的可持久化平衡树一般就是 可持久化无旋转 Treap ,省去了旋转可持久化的复杂。 【AgOHの数据结构】可持久化数组 方案: a. fat nodes 每个节点放所有历史,查询时在所有历史版本中找最近祖先版本 b. path copying 存到可持久化线段树里。 为什么好好的线性结构要树化?直觉上理解,是为了分裂新版本时减少指针复制。 如果是稀疏数组,朴素方法太浪费空间了,可以基于动态开点来优化空间存储,见 【AgOHの数据结构】可持久化并查集 并查集基于数组,可持久化并查集就基于可持久化数组。可持久化数组用可持久化线段树实现,因此可持久化并查集用可持久化线段树实现 《 可持久化数据结构研究 》 不过文中写的太简略了,个人推测的维护方法为: 讨论支持如下操作的抽象数据结构(ADT)如何可持久化: a. 基于普通数组 只能copy on write b. 基于可持久化数组/可持久化线段树 问题是怎么处理新增节点、删除节点?得想办法魔改线段树 c. 可持久化链表 d. 可持久化块状链表 e. 可持久化平衡树 f. 文中提到的vector trie 名字挺骚的没反应过来,看了一会发现:这玩意就是可持久化数组(可持久化线段树),只不过是多叉树,叫“可持久化多叉线段树”比较形象。文章也没提怎么处理新增节点、删除节点。 persistent-hash-table-implementation a. 可持久化平衡树 b. 还用hashmap,但是每个entry改造成fat node(存放所有log),查询时先找到entry,再在所有log 中找最近祖先版本 c. 可持久化数组。 考虑到HashMap本来就能只用一个数组实现(解决冲突时用open addressing方法,不用Chaining),那么实现了可持久化数组就相当于实现了可持久化HashMap d. Hash_trie hash(key)的值存在trie里,value放到trie的叶子节点。优化版本包括 Hash array mapped tries and Ctries HAMT这名字起的很奇怪。原理就是块状hash trie(所谓块状是我自己起的名,指每个节点区分儿子时不是单纯的比较某1位,而是比较某2位甚至多位)(或者理解成hash trie+动态开点多叉线段树也行)(反正就是bitwise hash trie加上一堆优化,懒得记就记hash trie就行了,真要自己实现的时候这些优化trick也能想到) 文中讲hamt的碰撞处理有点扯,个人理解可以chaining,可以open addressing。细节没深究,可以看 论文 和 讨论 。按作者的意思AMT是之前他提出的一种Trie的优化,比Tenary search trie要好。 // TOOD Planar Point Location问题见 朴素的方法是线段树套线段树,以便支持二维RMQ,时间复杂度O(logN*logN)。 个人理解,最优的二维RMQ数据结构应该是用modification box实现的可持久化值域线段树,O(N)的构造时间、空间,O(logN)的查询。 如果统计操作具有“区间可加性”、“区间可减性”,那么该操作二维统计问题可以使用可持久化线段树。 range minimum query中的min()操作其实不具有区间可减性,但是range minimum query问题可以归约成range select query问题,进而可以归约成range count query问题,而count()操作具有区间可加减性,因此也能用可持久化线段树。 所以我们得到了一类二维统计问题的通用数据结构:对于可归约成具有“区间可加性”、“区间可减性”统计操作的二维统计问题,可以使用可持久化线段树存储,以便支持快速查询(统计)。 能否找到一类高维统计问题,具有通用的logN级别解?个人理解可以借鉴代数的思想,只要有区间可加减性的都能归约成K维RMQ问题,用modification box实现的可持久化值域线段树解决。 // TOOD 只是个人畅想,没细想。 bigtable(hbase)可以看成外存模型下的可持久化map: 但需要注意的是删除操作会真的删掉之前的老版本数据: 其实任何支持前缀匹配的db都能作为可持久化map,你只需要把rowkey设计成"key@@timestamp"即可
素素V587
Interest rate marketability and our country State-owned Commercial bank countermeasureInterest rate marketability connotationThe so-called interest rate marketability, is refers to the money market fund supply and demand both sides independent determination interest rate level interest rate decision mechanism vicissitude process 。Says specifically, the interest rate marketability is refers to the Central Bank to need to regulate the datum interest rate according to the monetary policy, various commercial bank saves the loan interest rate according to the fund market supply and demand change independent adjustment, Finally forms take Central Bank datum interest rate as the guidance, multi-level, can manifest fund supply and demand condition and the reflection Central Bank monetary policy intention interest rate operational mechanism fully。The interest rate marketability emphasis interest rate really reflected the fund cost and the supply-demand relation, effectively display its economical leverage nimbly。一. Our country interest rate marketability reform existence questionIs opposite says in the Chinese economic reform and the opening to the outside world overall step, the interest rate marketability reform progresses slowly. Looked on the present situation that, our country not yet completely realizes the interest rate marketability, the interest rate control creates the interest rate this important price release lever to receive the serious restraint in the resources disposition aspect function, the interest rate structure distortion. Our country interest rate system marketability degree quite is also low, mainly displays in following several aspects:1. The interest rate control degree is high, the interest rate level and the structure are incompatible, and the bank independency is restricted. The current our country interest rate policy movement environment controls the interest rate primarily, the interest rate level decision, the difference interest rate policy making and so on the related interest rate each aspect policy all by the government strict control, displays the high planning and . The interest rate level determination has certain subjective blindness; the rate adjustment flexibility is insufficient. At present our country interest rate level decision is makes by the monetary policy committee, the interest rate decision-making power high degree of concentration in the central authorities, the interest rate formulation and the adjustment has the serious time lag . Lacks the effective market datum interest rate. On November 1, 2003, the NAP Standing Committee Cheng Sewer, vice chairman of the Forum, said: "The market-oriented interest rates, the key is to set the benchmark interest rate. The benchmark interest rate is determined, in order to determine the interest rate structure, risk structure. No established the benchmark rate, the interest rate market is a empty sentences. "Benchmark rate in the entire interest rate system has played a core role and prevents other interest rates, in a sense, the benchmark interest rate options and determine the interest rate market is the core of the reform steps.二.Implements the interest rate marketability state-owned commercial bank significanceFirst, is advantageous to the expansion state-owned commercial bank right of autonomous management, the enhancement competitive power. After the interest rate lets loose, the bank had the independent fixed price power, may use this kind of right to independence and its flexible full display fully. The various countries' reform experience indicated that, after the interest rate marketability, the deposit real interest rate all has the different scope raise. The real interest rate rise will have the positive influence to the deposit, the attraction fund from bank systems and so on the stock market, black market accepts the human bank system, the enhancement commercial bank's competitive power. Next, is advantageous in raises the state-owned commercial bank management level. The interest rate marketability causes the fund price to let loose truly. Price competition between the banks presents the new ball game from this. But the price competition must rise take the low cost fund as the backing. In order to gain the low cost capital source, various bank in the financial product, the marketing strategy, service method general unfolds manager respectively, this will intensify inevitably the competition intense degree, will urge the bank change management way, who will grasp is initiative who to be able to obtain market (In the new situation, the commercial bank guild cared about the interest rate market change situation and the international interest rate undulation tendency, and according to own situation, determines the cost scientifically, formulates the price reasonably, the enhancement economic accounting, strengthens its profit ability. It can be said that, the interest rate marketability reform, the interest rate production mechanism transformation, is to a commercial bank management and operation from inside to outside comprehensive forging. Is once more advantageous in creates a relatively fair competition environment. The interest rate marketability and the money market consummation is a process which complements one another. The developed money market is the interest rate marketability reliable guarantee. Because in the developed consummation money market, the financial tool type is rich, financial main body multi-dimensional, the financing way is diverse, the competition is full, the interest rate can reflect fully the fund price, can guide the resources reasonable disposition, enhances the resources use efficiency. Otherwise, the interest rate marketability can promote the money market development consummation; The money market is the interest rate marketability advancement beginning, also will be carries on the risk management to the interest rate the place, the interest rate system change promotes the money market development. Finally, is advantageous in speeds up the microscopic main body the property right reform, interest rate marketability important condition is the state-owned enterprise and the state-owned commercial bank's property right must be clear. The property right is not clear, is not strong to the interest intrinsic budget restraint, exceeds the time limit the risk responsibility to attenuate, and cannot be keen to the interest rate reflection. At present, our country State-owned Commercial bank and very big part of state-owned enterprise's property right slurred, the interest rate market changed into its reform to provide the power, on objective impelled their property right reform.三.The interest rate marketability causes the state-owned commercial bank faced with to challenge sternlyThe interest rate marketability, is the historical stage which our country Commercial bank must pass through, can impel our country State-owned Commercial bank enormously the reform. But after the interest rate marketability, the interest rate level change does not decide, Our country Commercial bank which survives under the control possibly can develop the new financial tool for a long time to dodge the interest rate risk without enough time, will certainly to face the stern challenge, this displays in:1.Has enlarged the bank rate risk. After the interest rate marketability, the interest rate level ascension and the irregular undulation enlarge, intensified the bank vulnerability, ha have enlarged the bank rate risk. After the interest rate marketability, the interest rate level ascension and the irregular undulation enlarge, intensified the bank vulnerability, have the possibility to cause the bank crisis extremely the occurrence. As a result of our country long-term interest rate control, the interest rate by artificial force down, after the interest rate is let loose, the interest rate level can elevate inevitably. The analysis indicated that, in the credit activity, along with the real interest rate enhancement, the risk borrower more will become the bank by chance the customer, But loathes the risk originally the enterprise borrowers also favor in change oneself project the nature, enable it to have a higher risk and the income level. The cause property average horizontal drop in quality, the credit risk , from looked for a long time that, the interest rate change the fund supply and demand real-time influence, can undulate frequently, but the interest rate undulation namely meant risk existence. How forecast accurately the interest rate change tendency, the reasonable determination has the competitive advantage price water; how assigns scientifically saves, the loan deadline layout, maintains the best advantage bad level;How forecast accurately the interest rate change tendency, the reasonable determination has the competitive advantage price water � How assigns scientifically saves, the loan deadline layout, maintains the best advantage bad level; How adjusts the property debt structure nimbly,Enhances prepares pays the level, the active control interest rate forms fluid wind �? How will supervise perfectly restricts the mechanism, prevented has human sentiment interest rate risk and so on, these will all cause the commercial bank faced with the stern .Leads the service to the commercial bank to have the huge impact. Along with the interest rate marketability, various bank launches the intense contention superiority customer to save the loan war inevitably, the keen competition will cause to save the loan advantage difference large scale deflation. At the same time, the interest rate marketability impetus money market development, the massive enterprise temporary fund no longer rises in value through the deposit form, but is in the capital market, the money market puts in obtains the short-term to receive;Whether there is does the inhabitant also no longer excessively regard as important only contains the risk value deposit interest rate, pays attention contains the risk value the money market to receive �? The bank leadership service will be under the huge can be said, after interest rate marketability, bank true competition magic weapon instead outside interest rate method. Because the monetary fund is highly the homogeneity commodity, the grade of service is more important, highly effective, the low cost manages finances the service enable the customer to have a higher income, has the attraction to the .Proposed the challenge to the bank management and interest rate control system, regardless of is the interest rate level or counts the rest method all to have the country to decide, regardless of how the country does adjust saves the loan interest rate, all fully considered commercial bank actual situation, maintains the reasonable advantage bad level throughout. Commercial bank's interest rate management is extremely simple, so long as gives according to the People's Bank the fluctuation scope carries out the national interest rate level then, the interest rate change is limited, the interest rate risk is controllable. In such situation, the bank management is inevitably passive. But in under the interest rate marketability condition, the intense market competition forces the bank either to use the price method, through raises the deposit interest rate, reduces the loan interest rate to attract the customer; Either depends upon the high quality service, through the function innovation, the product innovation, the technological innovation satisfies the customer. But this request commercial bank changes present the management, the method and the organization .Proposed the challenge to the commercial bank staff quality. Along with interest rate marketability reform advancement quickening, the interest rate risk enlarge, will strengthen to the future interest rate trend analyzes and forecast oneself will be very urgent. The state-owned commercial bank seeks the financial professional who needs one batch of this aspect high quality, not only these people must have the deep theory foundation of basic skills, but also must have the rich commercial bank practice experience, Both must thoroughly understand the domestic interest rate change the undulation condition, and must be skilled in the forecast interest rate change tendency. But the present state-owned bank lacks generally can promptly effectively the control and the circumvention interest rate risk tool and the interest rate risk management professional, to the interest rate trend development forecast, the risk recognition and control is weak.四.The state-owned commercial bank should to strategyAlong with the interest rate marketability advancement, the interest rate is more and more big to the state-owned commercial bank's influence, in this situation, the state-owned commercial bank should seek positively should to the .Establishment finance product fixed price system. In the interest rate marketability situation, whether does the commercial bank draw up a science reasonable fixed price system, has the nimble effective quoted price ability, the realization risk �? Between 20 income balances,Is key which whether it does develop continually. In this process, must establish the effective comprehensive income reckoning system, the overall evaluation customer comprehensive income which brings to the commercial bank,The customer credit risk size, the loan deadline length is the interest rate risk size, as well as commercial bank's collection fund cost and the operation cost share and so on the aspect questions。2.Increases the middle service product development ability, the adjustment profit structure. After the interest rate marketability, the bank saves, the loan favorable difference reduces, the profit level reduces, and this request state-owned commercial bank must develop the middle service vigorously. The bank may while develop positively receives on another's behalf, pays on another's behalf and so on service, uses the commercial bank market main body qualifications fully, positively provides the proxy for other financial organ to distribute the bond, the silver card account transfer, the proxy insures, the fund trust, the broker manages finances, The property management, financial consultant, the investment consultation and so on, enhances the middle service to buy a girl child, on own initiative develops the low risk, the high income middle service new variety positively, promotes the bank large scale by this profit ability, promotes the bank sustainable .Establishes nimbly, the highly effective interest rate management organization, trains the interest rate managerial talent vigorously. According to the Bethel bank supervising and managing committee about the bank effective supervising and managing core principle request, under the interest rate marketability environment, various commercial bank must set up the specialized interest rate risk management department, manages and instructs the entire good interest rate work, Coordinates and coordinates inside and outside the bank to be connected the work. The interest rate control section's most important task is carries on the comprehensive interest rate sensitive tube on the bank asset debt level ; Exterior determination, internal advantage � The definite general headquarters to branch office's interest rate authorization, are responsible for staff interest rate risk management training and so on. In addition, but also should establish the high interest rate information communication channel, after the interest rate marketability, the commercial bank interior enhances greatly about the interest rate information transmission effectiveness, guarantees can transmit promptly general headquarters formulation each interest rate to commercial bank's any business mesh point, guarantees the commercial bank interest rate policy the .Speeds up the state-owned commercial bank the property right reform. Stipulated according to "Law of corporation" that, the commercial bank belongs to the competitive profession, does not need to adopt the state-owned sole ownership property right, and does not have the legal barrier to its joint stock system transformation. To the state-owned commercial bank's property right reform, its concrete transformation form establishes the joint stock system commercial bank. The reality in China, in accordance with international practice, and gradually achieve solely by the state to transform the state-owned holding company, and ultimately joint-stock limited companies, and establish corporate system of corporate governance institutions, the establishment of the right to operate, ownership and the right to supervise the separation of the framework, China's commercial banks to become real significance of commercial banks, do business operations.字太多,发布下,你再见个问题吧,我回答。率市场化与我国国有商业银行对策利率市场化的内涵所谓利率市场化,是指金融市场资金供求双方自主确定利率水平的利率决定机制的变迁过程。具体讲,利率市场化是指中央银行根据货币政策的需要调控基准利率,各商业银行根据资金市场的供求变化自主调节存贷款利率,最终形成以中央银行基准利率为引导,多层次、能够充分体现资金供求状况和反映中央银行货币政策意图的利率运行机制。利率市场化强调利率真实地反映资金成本与供求关系,灵活有效地发挥其经济杠杆作用.
西西和嘻嘻
Make Every Document a Marketing Document Every scrap of paper that leaves your business is performing a marketing 's idea is not earthshattering, but it is one that many businesses, large and small, send invoices, fax covers, memo, notes, request and all other manner of "non-marketing" related correspondence to - you guessed it, your clients, referral sources and 's a pretty simple thing to A) make sure that these documents also conform to the image you project in your marketing materials and B) make them sell a no harm in introducing a new product in every communication, regardless of how mundane.
招财KItty.
场景几何的三维度量重建在刑侦现场勘查中的研究和应用 摘要三维重建属于Marr计算理论框架中的中级视觉部分,它是计算机视觉的主要研究内容。三维重建及可视化技术的研究在刑侦现场勘查、虚拟现实等方面具有重要的学术意义和应用价值。本文对三维重建进行深入的理论分析和研究,主要研究内容如下:l)对摄像机标定方法的分析和研究:摄像机标定方法是三维重建技术中的关键,本文在分析摄像机模型及成像原理的基础上,分析比较了各种摄像机标定方法,给出了各类方法的使用范围和应用条件。2)提出了一种可处理畸变因子和主点己知但其它内部参数发生变化的摄像机自定标方法。针对摄像机的位置改变需要重新标定的问题,本文提出了一种自标定方法。首先计算图像间的基本矩阵,在计算基本矩阵后得到射影重建的基础上,用线性方法恢复同形矩阵,再利用同形矩阵计算摄像机内部参数,实验结果验证了该方法的有效性。3)提出了一种仅须单幅图像的三维度量重建方法。针对图像序列的三维场景图像的层次化度量重建方法都首先进行射影重建的问题,本文提出了一种不必进行射影重建且只须单幅图像的三维度量重建方法。在平面型场景图像三维度量重建的基础上得到不同平面的度量重建,确定平面间的线段的长度比和相对方位,最后得到三维物体的度量重建,仿真实验证明了该方法的正确性。本项研究得到公安部B类部级重点项目“刑侦现场勘查可视化平台”(20036125301)的资助 ABSTRACT 3DreeonstruetionbelongstotheiniermediatevisionP献 intheframeworkof MarreomPutingtheoryandthePrimaryresearehingeontentineomPutervision. Researehon3Dreeonstruetionandvisualizationteehnologyhasin1Portantaeademie meaningsandapPlicationvaluesinerimeseeneinvestigation, virtualrealityandetc. Inthethesis, 3Dmetriereeonst几 etion15deePlyanalyzedandresearchedinitstheory , thebasisofanalyZingeameramodelsandimagingPrineiPles, variouseamera , anoveleameraself-ealibrationmethod15ProPosed, undertheeondition thattheeamera, 5distortedskewsandPrineiPalPointsarealready如own, andthe , 5Position, , toealeulatethefundamentalmatrixbetweenimagestoobtainProjeetive reeonstructionatfirst, andonwhiehbasisthen, toregainthehomographymatrixby linearmethod, atlast, toobtainthecamera, 5intrinsieParametersusinghomograPhy ,a多 metriereeonstruetionofseeneimage15oftenaimedtotheimagesequenees, andthe Stratifiedmetriereeonstruetionmethod15toobtaintheProjectivereeonstruetionof , the3Dmetrie reconstructionsofdifferentPlansareaequiredbasedonthe3Dmetriereeonstruetions showthevalidityofthemethod. Theresearehwork15fundedbytheMinistryofPublieSeeurityBlevelkeyProjeet‘ theVisualPlatformofCrimeSeene玩vestigation’ (). 你好,我有相关论文资料(博士硕士论文、期刊论文等)可以对你提供相关帮助,需要的话请加我,761399457(QQ),谢谢。
随着人类社会的快速发展,英语在不同国家的地理环境里和社会政治、经济、 文化 影响下发展状况自然不尽相同甚至产生了很大的变化。下文是我为大家整理的关于本科英文
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