数学日记

数学是科学的皇后 - 高斯

 

常识、模型、原理、数学、逻辑与思维

maxluo1990:

常识:人们(一定范围)所共同认可一些认识,它不证自明,大家都信,并多数人遵从。

模型:对实际存在的对象的符号化和抽象化描述。这里展示的是构想的或者实际存在的对象的某些关系和存在的属性。依据其中的某些特征,在具体的语境下可以代表那个物的实际存在或构想对象的实际存在。(关系和属性,是两大特征)

原理:类似于模型,是对存在的事物或构想物的规律(关系和属性)的描述和展示。也是适用于某一个前提的一种存在。往往是经过验证和测试的,可以用来指导行动的一种存在。

数学:从最开始的研究世界的各种事物的数量属性,到达研究世界事物的几何属性,最后到达研究构想物的属性的属性...

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大学生毕业论文设计:平面图的Dunbar猜想


•学号:PB06001074
•姓名:王晶
•年级:06级
•系别:数学系
•完成日期:2010年6月
•指导教师:徐俊明
•学校:中国科学技术大学


摘要:
对一个非空图G(graph), 如果G中的每一个顶点都在D 中或者与G的顶点相连,那么 D就被称为非空图的控制集 (dominating set),最小的 控制数(dominating number) 我们就用γ(G)表示。设E为 为G的一个边的集合,如果G- E的控制数大于G的控制数, 那么最小的集合E中边的数目 就称为束缚...

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关于狄拉克Delta函数

Diary upon the Stars:

这个函数,可是折腾过我一段时间。在一般的量子力学教材中,都没有能把它的数学问题解释清楚。我还特地问过清华的学长,发现学长根本不清楚,糊弄了过去。后来特地问了苏钧学长,才得到解答。

今天看到了一篇极好的科普文,记录在此,以供未来查阅。http://blog.sciencenet.cn/blog-826653-895613.html

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[R]回归分析pt.1——线性回归模型案例

Sirius:

跟着书上的东西做了一个案例。

> year=rep(2008:2010,each=4)
 > year
  [1] 2008 2008 2008 2008 2009 2009 2009 2009 2010 2010 2010 2010

> quarter=rep(1:4,3)
 > quarter
  [1] 1 2 3 4 1 2 3 4 1 2 3 4

> cpi=c(162.2,164.6,166.5,166.0,
 + 166.2,167.0,168.6,169...

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复变函数的对称原理

Diary upon the Stars:

可用作解析延拓的一种方式。

设U位于直线l的同一侧,其边界包含l上一线段s(端点不在内)。若f(z)在U上全纯,在UUs上连续,且f(z)在s上的值位于直线L上,则存在F(z)在UUU'Us上全纯,在U内F(z)=f(z),这里U’为U关于l对称的域。若z1,z2为UUU'Us内关于l对称的两点,则F(z1),F(z2)是关于L对称的两点。

虽然快要考试了,但是今天晚上我还是忍不住想了一个问题。证明Xi函数在Rez=1/2的直线上是实数。想了很久很久,一直想偏了,最后还是想对了。首先,Xi函数在整个实轴上都是实数,又Xi(1/2+it...

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泠淞:

啦啦啦~我画成功啦~

  14

泠淞:

画得包络一只~^_^~

  9

正弦和余弦(随便写点三行诗)

练个笔:

人人都以为他们是天生一对
但他却觉得自己罪孽深重
而她,只知道伪装成别人的样子

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Web Technology:

IT 计算机信息网络安全技术:

Mozilla Online Website Two Sub-Domains XSS (Cross-site Scripting) Bugs ( All URLs Under the Two Domains)



Domains:
http://lxr.mozilla.org/
http://mxr.mozilla.org/
(The two domains above are almost the same)




Websites information:
"lxr.mozilla.org, mxr...

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IT 计算机信息网络安全技术:

All Links in Two Topics of Indiatimes (indiatimes.com) Are Vulnerable to XSS (Cross Site Scripting) Attacks



(1) Domain Description:
http://www.indiatimes.com


"The Times of India (TOI) is an Indian English-language daily newspaper. It is the third-largest newspaper...

  21

Math and Computer & Web Security - Cryptography


A military commander wants some assurance that the information sent to field commanders does not fall into the hands of opponents. Hence, written communications which can be easily read if intercepted by an an enemy are dangerous. (Asking the...

  1

行者路上有風有雨有彩虹:

琐事,日常之事:

爱情比翼:


熱帶雨林 - S.H.E - 青春株式會社 柔美溫和華文歌曲


高中的時候,第壹次從同學那聽到這首歌,喜歡無比。如今,多年已過,物是人非,做壹視頻以自慰,紀念曾經的青春。"熱帶雨林" 采用柔美溫和的旋律,讓人容易回憶起往事,采用傷感又令人感動的歌詞,易引起聽眾的共鳴。歌曲通過三人的完美配合,表達出了青春期少男少女中感情受困如置 身夢境、迷失在熱帶雨林的感覺



音樂
所屬專輯: "青春株...

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IT 计算机&信息网络 技术:

Web Technology:

CVE-2014-8753  Cit-e-Net Multiple XSS (Cross-Site Scripting) Web Security Vulnerabilities


Exploit Title: Cit-e-Net Multiple XSS (Cross-Site Scripting) Web Security Vulnerabilities

Product: Cit-e-Access

Vendor: Cit-e-Net

Vulnerable...

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IT 计算机信息网络安全技术:

About Group (about.com) All Topics (At least 99.88% links) Vulnerable to XSS & Iframe Injection Security Attacks, About.com Open Redirect Web Security Vulnerabilities


Vulnerability Description:
About.com all “topic sites” are vulnerable to XSS (Cross-Site Scripting) and Iframe

  18

湛天雲海碧波影:

IT 计算机&信息网络 技术:

白帽子计算机安全:

CNN Travel.cnn.com XSS and Ads.cnn.com Open Redirect Web Security Vulnerabilities


Domain:
cnn.com


"The Cable News Network (CNN) is an American basic cable and satellite television channel that is owned by the Turner...

  19

湛天雲海碧波影:

Green Life 的喜欢:

IT 计算机&信息网络 技术:

ESPN espn.go.com Login & Register Page XSS and Dest Redirect Privilege Escalation Web Security Vulnerabilities


Domain:
http://espn.go.com/


“ESPN (originally an acronym for Entertainment and Sports Programming Network...

  17

琐事,日常之事:

日常生活點滴的記錄:

测试想法:

Yahoo Yahoo.com Yahoo.co.jp Open Redirect (Unvalidated Redirects and Forwards) Web Security Bugs


Though Yahoo lists open redirect vulnerability on its bug bounty program. However, it seems Yahoo do not take this vulnerability seriously at all....

  20

IT 计算机信息网络安全技术:

Google DoubleClick.net (Advertising) System URL Redirection Vulnerabilities Could Be Used by Spammers


Although Google does not include Open Redirect vulnerabilities in its bug bounty program, its preventive measures against Open Redirect attacks have been quite thorough and...

  20

测试想法:

行者路上有風有雨有彩虹:

IT 计算机&信息网络 技术:

Facebook Old Generated URLs Still Vulnerable to Open Redirect Attacks & A New Open Redirect Web Security Bugs

Domain:
http://www.facebook.com



"Facebook is an online social networking service headquartered in Menlo Park, California...

  18

琐事,日常之事:

IT 计算机信息网络安全技术:

Internet Users Threatened by New Serious Security Flaw, Covert Redirect


A serious flaw in two widely used security standards could give anyone access to your account information at Google, Microsoft, Facebook, Twitter and many other online services. The flaw...

  22

IT 计算机&信息网络 技术:

IT 计算机信息网络安全技术:

白帽子计算机安全:

Alibaba Taobao, AliExpress, Tmall, Online Electronic Shopping Website XSS & Open Redirect Security Vulnerabilities




Domains Basics:
Alibaba Taobao, AliExpress, Tmall are the top three online shopping websites belonging to Alibaba....

  16

The Art of Study:

sketchshoppe:

Today at the library: History of Astronomy


  7

Looks Like Physics:

非欧几何~

educational-gifs:

Drawing three 90 degree angles in a curved space. One of the reasons we know the Earth is round.

Find this interesting? Then check out this “visual demonstration of a² + b² = c².


  46

Quantum-Spacetime:

The Beginning of Everything — The Big Bang

A beautifully animated description of what we know about the creation of the Universe, so far. 
We can see most of the how, though who knows how long this can last. Does the universe build in enough time for the beings that study...

  2

Looks Like Physics:

hyrodium:

Sorry for being late.
I made two ways of graphical explanation of Euler’s formula.
This explanation is the same as wikipedia.
Another explanation post is coming soon.

Fig 1
The N-th power of a (complex number) is located as shown, and all triangles are similarity...

  5

Looks Like Physics:

寒假回家了 我也试试~~

kqedscience:

popmech:

Chilly.

Way cool.


  28

大盗贼*yodobashi:

东京西郊高尾山顶,看到的富士山。

  193

Cosplay写真馆:

可爱的小短刀五虎退~

夏神樂:

『刀劍亂舞﹣五虎退』

Cosplay攝影預告

僕があの、五虎退です。謙信公へのお土産です。
その時、なんというか、調子のいいお話がつけられて、僕、虎をいろいろやっつけたことになったんですけど。
ぐす。ほんとはただの短刀でぇ・・・ぐす


攝影:夏神樂 @_夏神樂 

五虎退:錢Kane @錢Kane

協力:Raetsel

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别人的手机:

Sex Gun:

说了等于不说的才是情话

  984

别人的手机:

waSabi:

你是否也在海的那一边,等待狂风暴雨,潮起潮落。

   
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