信息系统项目管理教程-信息的基本概念
前言
信息是一种答观事物，它与材料、能源一样，都是社会的基础资源。但是，理性认识信息却只有几十年的历史。1948年，美国科学家香农（Claude E.Shannon）在对通信理论深入研究的基础上，提出了信息的概念，创立了信息理论（人们通常将香农于1948年10月发表的论文《通信的数学理论》（A Mathematical Theory of Communication）作为现代信息论研究的开端）。
此后，人们对信息的研究迅速增加，形成了一个新的学科--信息论。至今，信息论已发展成为一个内涵非常丰富的学科，控制论和系统论并称为现代科学的“三论”。计算机技术和网络技术的迅速发展和普及，更加重了“三论”在现代科学技术中的地位。同时，信息论为计算机技术和网络技术的发展提供了方向上的指导，为信息化提供了较好的理论支撑。
信息的基本概念
香农指出，信息就是能够用来消除不确定性的东西。香农不但给出了信息的定义，还给出了信息的定量描述，并确定了信息量的单位比特（bit）。1比特的信息量，在变异度为2的最简单情况下，就是能消除非此即彼的不确定性所需要的信息量。这里的“变异度”是指事物的变化状态空间为2，例如，大和小、高和低、快和慢等。
香农将热力学中的输引入信息论。在热力学中，熵是系统无序程度的度量，而信息与熵正好相反，信息是系统有序程度的度量，表现为负熵，计算公式如下：
上述算式中，xi代表n个状态中的第i个状态，p(xi)代表出现第f个状态的概率，H(x)代表用以消除系统不确定性所需的信息量，即以比特为单位的负熵。
信息的特征
香农关于信息的定义揭示了信息的本质。
同时，人们通过深入研究，发现信息还具有很多其他的特征，举例如下：
（1）客观性。信息是客观事物在人脑中的反映，而反映的对象则有主观和客观的区质，因此，信息可分为主观信息（例如，决策、指令和计划等）和客观信息（例如，国际形势、经济发展和一年四季等）。主观信息必然要转化成客观信息，例如，决策和计划等主观信息要转化成实际行动。因此信息具有客观性。
（2）普遍性。物质决定精神，物质的普遍性决定了信息的普遍存在。
（3）无根性。客观世界是无限的，反映客观世界的信息自然也是无限的。无限性可分为两个层次，一是无限的事务产生无限的信息，即信息的总量是无限的，二是每个具体事物或有限个事务的集合所能产生的信息也可以是无限的。
（4）动态性。信息是随着时间的变化而变化的。
（5）相对性。不同的认识主体从同一事物中获取的信息及信息量可能是不同的。
（6）依附性。信息的依附性可以从两个方面来理解，一方面，信息是客观世界的反映，任何信息必然由客观事物所产生，不存在无源的信息；另一方面，任何信息都要依附于一定的载体而存在，需要有物质的承担者，信息不能完全脱离物质而独立存在。
（7）变换性。信息通过处理可以实现变换或转换，使其形式和内容发生变化，以适应特定的需要。
（8）传递性。信息在时间上的传递就是存储，在空间上的传递就是转移或扩散。
（9）层次性。客观世界是分层次的，反映它的信息也是分层次的。
（10）系统性。信息可以表示为一种集合，不同类别的信息可以形成不同的整体。
因此，可以形成与现实世界相对应的信息系统。
（11）转化性。信息的产生不能没有物质，信息的传递不能没有能量，但有效地使用信息，可以将信息转化为物质或能量。
由于获取信息满足了人们消除不确定性的需求，因此信息具有价值，而价值的大小决定于信息的质量，这就要求信息满足一定的质量属性，包括：
（1）精确性。对事物状态描述的精准程度。
（2）完整性。对事物状态描述的全面程度，完整信息应包括所有重要事实。
（3）可靠性。指信息的来源、采集方法、传输过程是可以信任的，符合预期。
（4）及时性。指获得信息的时刻与事件发生时刻的间隔长短。昨天的天气信息不论怎样精确、完整，对指导明天的穿衣并无帮助，从这个角度出发，这个信息的价值为零。
（5）经济性。指信息获取、传输带来的成本在可以接受的范围之内。
（6）可验证性。指信息的主要质量属性可以被证实或者证伪的程度。
（7）安全性。指在信息的生命周期中，信息可以被非授权访问的可能性，可能性越低，安全性越高。
信息应用的场合不同，其侧重面也不一样。例如，对于金融信息而言，其最重要的特性是安全性，而对于市场信息而言，其最重要的特性是及时。
信息的功能
信息在人类认识世界和改造世界的过程中与物质、能源一样，发挥着十分重要的作用。其主要功能如下：
（1）为认识世界提供依据。人们认识世界，首先要获取认识对象的有关信息，并通过对这些信息的加工获得有关知识，从而形成正确的认识。
（2）为改造世界提供指导。人们认识世界的目的是改造世界，而改造世界就必须有正确的观金作指导。这些观念包括活动的计划、环境分析、结果的预测和发展变化的对策等，这些都离不开信息的指导。
（3）为有序的建立提供保证。人们所有活动的目的都是使得客观世界变得更加有序。
这种有序至少要包括两种情况，一是使得本来有序的客观世界得到改善，变得更加有序。
二是打破原来的有序，建立一种新的有序。无论哪种情况，都需要有信息的保证。
（4）为资源开发提供条件。人类社会的生存和发展要建立在资源之上，所有这些源可分为两类，即有形资源和无形资源。有形资源包括物质和能量，物质供给材料、能量供给动力，是人类发展的基础；无形资源主要是信息资源，信息供给智力，是人类发展的精神力量。无论是开发有形资源还是无形资源，都需要信息。
（5）为知识生产提供材料。生产是人类生存和发展的基础和前提，既包括物质产品的生产，也包括精神产品的生产，其中知识的生产是精神产品生产的主要内容，而信息则为知识的生产提供材料。
信息的传输模型
信息是有价值的一种客观存在。信息技术主要为解决信息的采集、加工、存储、传输、处理、计算、转换、表现等问题而不断繁荣发展。信息只有流动起来，才能体现其价值，因此信息的传输技术（通常指通信、网络等）是信息技术的核心。信息的传输模型，如下图所示。
·信源：产生信息的实体，信息产生后，由这个实体向外传播。如QQ使用者，他通过键盘录入的文字（如：您好！）是需要传播的信息。
·信宿：信息的归宿或者接收者，如使用QQ的另一方（当然这一方也是信源），他通过计算机屏幕接收QQ使用者发送的文字（如：您好！）。
·信道：传送的信息的通道，如TCP/IP网络。信道可以从逻辑上理解为抽象信道，也可以是具有物理意义的实际传送通道。TCP/IP网络是一个逻辑上的概念。这个网络的物理通道可以是光纤、同轴电缆、双绞线，也可以是4G网络，甚至是卫星或者微波。
·编码器：在信息论中是泛指所有变换信号的设备，实际上就是终端机的发送部分。它包括从信源
到信道的所有设备。如量化器、压缩编码器、调制器等，使信源输出的信号转换为信道传送的信号。在QQ应用中，键盘敲击会使键盘由不确定状态转换为某种确定状态，此时信息产生了，通过一系列的信号采集、加工、转换、编码，信息最终被封装为TCP/IP包，推入TCP/IP网络，开始传播之旅。
·编码器：还可以包括加密设备，加密设备利用密码学的知识，对编码信息进行加密再编码。
·译码器：译码器是编码器的逆变换设备，把信道上送来的信号（原始信息与噪声的叠加）转换成信宿能接受的信号，可包括解调器、译码器、数模转换器等。在上述QQ应用中，TCP/IP包被解析，信息将显示在信宿的电脑屏幕上，发送者传送信息的不确定性消除了。
·噪声：噪声可以理解为干扰，干扰可以来自于信息系统分层结构的任何一层，当噪声携带的信息大到一定程度的时候，在信道中传输的信息可以被噪声掩盖导致传输失败。
当信源和信宿已给定、信道也已选定后，决定信息系统性能就在于编码器和译码器。设计一个信息系统时，除了选择信道和设计其附属设施外，主要工作也就是设计编、译码器。一般情况下，信息系统的主要性能指标是它的有效性和可靠性。有效性就是在系统中传送尽可能多的信息；而可靠性是要求信宿收到的信息尽可能地与信源发出的信息一致，或者说失真尽可能小。为了提高可靠性，在信息编码时，可以增加冗余编码，犹如“重要的话说三遍”，恰当的冗余编码可以在信息受到噪声侵扰时被恢复，而过量的元余编码将降低信道的有效性和信息传输速率。
概括起来，信息系统的基本规律应包括信息的度量、信源特性和信源编码、信道特性和信道编码、检测理论、估计理论以及密码学。
文章评论（8）
Hi Everyone,
I want to send you good wishes & good health in your future studies.
I have a couple reading assignments for you.
1984 by George Orwell
Brave New World by Aldous Huxley
What is happening now is criminal. I urge you to write local and federal goverments and voice your disgust with how they are handling this situation.
You should voice your opinion everywhere you go.
You will not be manipulated by fear.
I urge you to do research and to think for yourself and question everything that government tells you.
Please share these links, we need to end this crime against us.
DO NOT SUBMIT TO TYRANNY, HAVE COURAGE TO DEFEND YOUR FREEDOM!
GOD BLESS YOU ALL
Hi there,
I hope you’re doing well, I handle influencer relations for LeggingsHut. Great to meet you!
I stumbled across your account and thought your content would be perfect for us. If you feel we’d make a good fit, I’d love to invite you to our referral program.
If you have any questions, just reply to this email.
judy999887@gmail.com
Sincerely,
LeggingsHut
Judy
Hey, this is Eric and I ran across testclass.cn a few minutes ago.
Looks great… but now what?
By that I mean, when someone like me finds your website – either through Search or just bouncing around – what happens next? Do you get a lot of leads from your site, or at least enough to make you happy?
Honestly, most business websites fall a bit short when it comes to generating paying customers. Studies show that 70% of a site’s visitors disappear and are gone forever after just a moment.
Here’s an idea…
How about making it really EASY for every visitor who shows up to get a personal phone call you as soon as they hit your site…
You can –
Talk With Web Visitor is a software widget that’s works on your site, ready to capture any visitor’s Name, Email address and Phone Number. It signals you the moment they let you know they’re interested – so that you can talk to that lead while they’re literally looking over your site.
You’ll be amazed - the difference between contacting someone within 5 minutes versus a half-hour or more later could increase your results 100-fold.
It gets even better… once you’ve captured their phone number, with our new SMS Text With Lead feature, you can automatically start a text (SMS) conversation.
That way, even if you don’t close a deal right away, you can follow up with text messages for new offers, content links, even just “how you doing?” notes to build a relationship.
Pretty sweet – AND effective.
You could be converting up to 100X more leads today!
Eric
PS: Talk With Web Visitor offers a FREE 14 days trial – and it even includes International Long Distance Calling.
You have customers waiting to talk with you right now… don’t keep them waiting.
Cool website!
My name’s Eric, and I just found your site - testclass.cn - while surfing the net. You showed up at the top of the search results, so I checked you out. Looks like what you’re doing is pretty cool.
But if you don’t mind me asking – after someone like me stumbles across testclass.cn, what usually happens?
Is your site generating leads for your business?
I’m guessing some, but I also bet you’d like more… studies show that 7 out 10 who land on a site wind up leaving without a trace.
Not good.
Here’s a thought – what if there was an easy way for every visitor to “raise their hand” to get a phone call from you INSTANTLY… the second they hit your site and said, “call me now.”
You can –
Talk With Web Visitor is a software widget that’s works on your site, ready to capture any visitor’s Name, Email address and Phone Number. It lets you know IMMEDIATELY – so that you can talk to that lead while they’re literally looking over your site.
CLICK HERE to try out a Live Demo with Talk With Web Visitor now to see exactly how it works.
Time is money when it comes to connecting with leads – the difference between contacting someone within 5 minutes versus 30 minutes later can be huge – like 100 times better!
That’s why we built out our new SMS Text With Lead feature… because once you’ve captured the visitor’s phone number, you can automatically start a text message (SMS) conversation.
Think about the possibilities – even if you don’t close a deal then and there, you can follow up with text messages for new offers, content links, even just “how you doing?” notes to build a relationship.
Wouldn’t that be cool?
CLICK HERE to discover what Talk With Web Visitor can do for your business.
You could be converting up to 100X more leads today!
Eric
PS: Talk With Web Visitor offers a FREE 14 days trial – and it even includes International Long Distance Calling.
You have customers waiting to talk with you right now… don’t keep them waiting.
CLICK HERE to try Talk With Web Visitor now.
If you'd like to unsubscribe click here
Hi,
My name is Eric and I was looking at a few different sites online and came across your site testclass.cn. I must say - your website is very impressive. I am seeing your website on the first page of the Search Engine.
Thanks and Best Regards,
Eric
Dear Sir/ Madam,
We are top quality SMD Power Inductors Maker and service carrier in Hong Kong.
High consistence, Rigorous QC, Leading CP ratio and also Full assistance in application is our toughness.
We comprehend that a person bad element ruins the entire product and also your online reputation.
Pick us to get rid of cheap and also rubbish SMD Power Inductors from China!
Expecting your queries!
Finest relates to,
Brian
HK Inductors LTD established in 1997, we are concentrated on creating and also producing high-performance inductors with the goal of supplying added-value product services to consumers in a wide variety of sectors.
Hey,
You have a website testclass.cn, right?
Of course you do. I am looking at your website now.
It gets traffic every day – that you’re probably spending $2 / $4 / $10 or more a click to get. Not including all of the work you put into creating social media, videos, blog posts, emails, and so on.
So you’re investing seriously in getting people to that site.
But how’s it working? Great? Okay? Not so much?
If that answer could be better, then it’s likely you’re putting a lot of time, effort, and money into an approach that’s not paying off like it should.
Now… imagine doubling your lead conversion in just minutes… In fact, I’ll go even better.
You could actually get up to 100X more conversions!
I’m not making this up. As Chris Smith, best-selling author of The Conversion Code says: Speed is essential - there is a 100x decrease in Leads when a Lead is contacted within 14 minutes vs being contacted within 5 minutes.
He’s backed up by a study at MIT that found the odds of contacting a lead will increase by 100 times if attempted in 5 minutes or less.
Again, out of the 100s of visitors to your website, how many actually call to become clients?
Well, you can significantly increase the number of calls you get – with ZERO extra effort.
TalkWithCustomer makes it easy, simple, and fast – in fact, you can start getting more calls today… and at absolutely no charge to you.
CLICK HERE now to take a free, 14-day test drive to find out how.
Sincerely,
Eric
PS: Don’t just take my word for it, TalkWithCustomer works:
EMA has been looking for ways to reach out to an audience. TalkWithCustomer so far is the most direct call of action. It has produced above average closing ratios and we are thrilled. Thank you for providing a real and effective tool to generate REAL leads. - P MontesDeOca.
Best of all, act now to get a no-cost 14-Day Test Drive – our gift to you just for giving TalkWithCustomer a try.
CLICK HERE to start converting up to 100X more leads today!
Hello testclass.cn,
People ask, “why does TalkWithCustomer work so well?”
It’s simple.
TalkWithCustomer enables you to connect with a prospective customer at EXACTLY the Perfect Time.
- NOT one week, two weeks, three weeks after they’ve checked out your website testclass.cn.
- NOT with a form letter style email that looks like it was written by a bot.
- NOT with a robocall that could come at any time out of the blue.
TalkWithCustomer connects you to that person within seconds of THEM asking to hear from YOU.
They kick off the conversation.
They take that first step.
They ask to hear from you regarding what you have to offer and how it can make their life better.
And it happens almost immediately. In real time. While they’re still looking over your website testclass.cn, trying to make up their mind whether you are right for them.
When you connect with them at that very moment it’s the ultimate in Perfect Timing – as one famous marketer put it, “you’re entering the conversation already going on in their mind.”
You can’t find a better opportunity than that.
And you can’t find an easier way to seize that chance than TalkWithCustomer.
CLICK HERE now to take a free, 14-day test drive and see what a difference “Perfect Timing” can make to your business.
Sincerely,
Eric
PS: If you’re wondering whether NOW is the perfect time to try TalkWithCustomer, ask yourself this:
“Will doing what I’m already doing now produce up to 100X more leads?”
Because those are the kinds of results we know TalkWithCustomer can deliver.
It shouldn’t even be a question, especially since it will cost you ZERO to give it a try.
CLICK HERE to start your free 14-day test drive today.