OpenLLM-France/wikimedia huggingface dataset:
# Principles of Economics/Economic Modeling
## Use of Models

Economists use models to analyze an economy with high-accuracy. A model is a theoretical framework that attempts to describe certain aspects of a real-world economic problem. The framework is usually based on mathematics, and most models make several assumptions about how people behave and how the modeled economy operates. Models allow economists to simplify complex problems to the point where they can be analyzed so that useful observations or predictions can be made.
Importantly, models are not intended to perfectly represent reality (see Assumptions Economists Make). Experimental results have often found that some of the most basic assumptions of economics do not hold true for large percentages of the population. On one hand, a model based on incorrect assumptions should be closely scrutinized to ensure those assumptions aren't returning results that don't hold in the real world. On the other hand, a model that is extremely accurate at making correct predictions about economic problems is useful whether or not its assumptions are fully correct.

## Methodology

Economics is a social science. Many aspects of the scientific method are incorporated into how economists do their work. Hypotheses are developed from observations. Data is used to test hypotheses. A proven hypothesis is used to make predictions. Economics is not exactly like a "hard science", though. Most economic hypotheses are tested using observational data, not controlled experiments. Behavioral and experimental economics are emerging subfields which attempt to use controlled experiments to test economic theories, but many theories do not lend themselves well to controlled experiments.
Economists both develop theory and apply theory to economic problems. A theoretical economist creates a model to explain an economic problem. An applied economist uses data to explain an economic problem. Many economists both develop theory and solve applied problems, and applied economists use aspects of existing theory when formulating their hypotheses, developing predictions, or determining cause-and-effect relationships.
# The Computer Revolution/Networks/Network Topologies/Mesh
## Mesh

There many different network topologies.Mesh network is widely used. Mesh networking is a topology where each node must not only capture and disseminate its own data, but also serve as a relay for other nodes. The network is redundant and fault tolerant. This makes it so that if one node goes
down it does not take the whole network with it.
This gives it self-healing capabilities. The network will change the route of the packets to a node that is still up and working. As a result, the network is typically quite reliable, as there is often more than one path between a source and a destination in the network.
Some of the advantages are as follows: Point to point line configuration makes identification and isolation of faults easy, messages travel through a dedicated line meaning that only the intended recipient receives the message, in the case of a fault in one link, only the communication between the two devices sharing the link is affected, and the use of dedicated links ensures that each connection carries its own data load thus eliminating traffic problems that would have been encountered if a connection/link was shared. Mesh networks are best for WAN, MAN and large LANs. For the average house hold this network is not recommend.
This is because the network will grow larger and expensive to maintain. The networks best for home use would be Star, Ad hoc, or bus. Ad hoc networks are a form of mesh network with the only difference being that every node connects directly to each other and not through a switch.
* ↑ http://en.wikipedia.org/wiki/Network_topology#Point-to-point
* ↑ http://en.wikipedia.org/wiki/Mesh_networking
* ↑ http://www.meshdynamics.com/
# The Computer Revolution/Networks/Short Range Wireless for Automation Networks

Home Automation Networks is what connects everything around a house. It connects them through switches and senors. It used a narrowband wireless technology which can operate between 100 and 250 feet. It is low powered and receives data slowly as compared to Personal Area Networks. it receives about 13.1-238 kilobits pers second. There are 3 current standards. They are Insteon, ZigBee and Z-Wave. These are referred to as "mesh technologies". Mesh Technologies are networked devices with two way radios so that they can communicate with each other with more than just the controller. It is the central command for the network. Insteon is a standard that incorporates wireless technology in with an electric power line. This is capable of sending up to 13.1 kilobits at a range of 150 feet. As the CEO describes, "drive up to your house, the garage door device recognizes yor car, and open to let you in. The lights come on and your favorite radio station starts playing." Insteon has replaced a older automation technology that was known as X10. ZigBee does not incorporate electric power lines into its technology therefore it is all wireless. ZigBee is very efficient, it can send up to 128 kilobits at a range of 250 feet. It is expected to be seen every from smoke detectors in your house to medical sensing devices. The best part is that it can function for a long time, on inexpensive batteries. Z-Wave also consists solely of wireless technology which is power efficient. It can send about 127 kilobits per second to a range of 100 feet. When you compare you would notice that Z-Wave and Insteon are very much similar. The only difference is that Insteon used electric power cables and Z-Wave doesn't.
# The Computer Revolution/Networks/WAN
### Wide Area Network

WAN is the computer network that covers a large geographical area, which usually consists of two or more smaller networks called LANs. The LAN network is the public network and it could run through the telephone lines or through satelites. Our personal computers are connected to the LAN network. The internet is the WAN network which is the largest network. The LAN networks could be public or privately owned. There are few WAN technologies used:
* point-to-point links - point to point links connects the customer's premise to the main network through a telephone circuit.Usually these connections are more expensive than the shared networks.
* circuit switching - the data communication is initiated when is needed and is disconnected when is not needed. It is similar to a voice service. Some wireless devices work on the ISDN network, which is usually faster and more reliable. ISDN is an example of circuit switching.
* packet switching - here customers share the carrier's network. The cost is usually cheaper for the customer and allows the carrier to use the network more efficiently.
* WAN virtual circuits - this is a shared network between two other networks
* WAN dial-up services - it is a very cheap way of initializing the network. Here the customer uses a telephone line to connect to the internet using on demand routing.
* WAN devices - there are switches, access servers, modems, ISDN adapters, routers and ATM switches.
# The Computer Revolution/Networks/Short Range Wireless for Personal Area Networks

Short range wireless technology is used to connect personal area networks to personal electronics. These could be your cellphone, you printers, your PDAs, your MP3 players and what not. So far the most famous is Bluetooth which is now joined with Ultra wideband (UWB). It is also connected with wireless USB. Bluetooth connects cellphones, PDAs, computers and other external devices on PCs. It is a short range wireless device so it can connect to devices up to 30 feet away. Bluetooth was at first designed to replace the hassle of cables that were connecting PCs to external devices such as printers and scanners and to overcome "line of sight" problems by using infrared transmission. The original version of Bluetooth technology could transmit up to 720 kilobits per second and was name after Harold Bluetooth who was a Danish King who united Norway and Denmark. The Ultra wideband was a technology developed by the military to increase transfer speeds to up to 480 megabits per second. At a 30 feet connection UWB sent out millions of waves of radio energy at different frequencies every second. The broken bits were then reassembled by the UWB receiver. Sometime along in this year it is predicted that cellphones will inherit this technology and will be able to transfer media from their PCs to their cellphones without adapters or cables. Wireless USB is based on this same technology (UWB). Ranging up to 32 feet it can still transfer up to 480 megabits per second and is said to be a natural replacement for USB cables.
# The Computer Revolution/Networks/Social Networks

Social networking is a phenomenon not relating to computers specifically, but made entirely possible by the likes of them. A social network is a way to stay connected to other people from anywhere in the world at all times over the internet. Social networking platforms vary by your preference of communication. Some of the more popular social networking platforms include Twitter, which requires the messages its users broadcast to their networks to be under a certain(small) character limit; Myspace, which has adapted a more music-entwined approach to capture a certain demographic; Facebook, the successor of Myspace as the most popular and massive network; and internet monolith Google's G+ platform(a Facebook competitor focusing on dividing your network into specific groups). All of the major networks are accessible from various sources such as a smartphone, a computer, even some TV's.
In addition to that Social Networking Sites are used to communicating with existing friends or making new friends, it also allows you to post photos, videos, music and other contents for friends. Furthermore, chatting with friends who are online is also possible through Social Networking Sites. On the other hand, today Social Networking Sites are even used as business marketing tool, by the help of which businesses, political candidates, emerging musicians, and other professionals or professional organizations make their presence online. Even, Social Networking Sites are designed for business networking which can in fact help to develop a business. LinkedIn is one of the Social Networking Sites used to for recruiting employees, finding new jobs, and building professional networks and other business related activities. Hence, today whole world is joining these Social Networking Sites with the help of which they can stay connected to friends or relatives residing in any corner of the world. Among all the Social Networking Sites Facebook has highest number of users today.

## Security risks associated with social networking

Nowadays, nearly everyone has access to an ever-popular Facebook or Twitter account. Social networking makes it easy to post personal information to the web. Whether it be as little as posting a family picture or as much as posting a home address, any and all information must be posted with caution. One of the most simply (yet tricky for some) is to simply avoid adding too many personal details about yourself on the web.
Here are a few thoughtful links of security risks on social networks:
http://www.focus.com/fyi/security-risks-social-networks/
http://www.microsoft.com/security/online-privacy/social-networking.aspx
# The Computer Revolution/Networks/VPN
### Virtual Private Networks

A VPN is a secure pathway through a public network that is used to allow private access to an institutions network. Many businessmen and women use this type of network to communicate with their company network securely using the internet. This communication is usually encrypted for the case that it ends up in the wrong hands. A VPN may be used to share data and give access to databases and printers.
VPN is a point-to-point connection across a private or public network, such as Internet. A VPN client uses tunneling protocols (special TCP/IP-based protocols) to make a virtual call to a virtual port on a VPN server. Typically, a client initiates a virtual point-to-point connection to a remote access server over the Internet. The remote access server answers the call, authenticates the caller and transfers data between the VPN client and the organization’s private network. VPN protects any communication that is carried out over a public network such as the internet. They can also provide several types of data protection including: confidentiality, integrity, data origin authentication, replay protection, and access control.
Data shared across a VPN is encapsulated or wrapped with a header. The header contains routing information that enables the data to travel through the shared or public network to reach its destination. To emulate a private link, the data is encrypted for confidentiality. Packets that are intercepted on the shared or public network are indecipherable without the encryption keys.
# The Computer Revolution/Networks/PAN
### Personal Area Network

Personal Area Network (PAN) is a network that connects an individual’s personal devices that are located close together to communicate and share data. Personal Area Networks can connect these devices up to 30 feet apart from the network location. Devices set up in a PAN can be a computer, printer, scanner, camera, and cellphone. The devices are set up to connect automatically when they are within a certain distance from each other. Wireless Personal Area Networks (WPANs) are connected wirelessly via Bluetooth, Infrared Data Association, or Wi-Fi. The Bluetooth is dependent on the power class of each device, which ranges from 1 to 100 meters to receive signal. The Infrared Data Association (IrDA) uses short-range communication using infrared light to transmit data.
* ↑ http://www.rfidc.com/docs/introductiontowireless_standards.htm
# The Computer Revolution/Networks/Types of Networks
## Hub

It is the central part of a wheel where the spokes come together. Hubs are more commonly found in wired networks. A common connection point for devices in a network. Hubs are commonly used to connect segments of a LAN. A hub contains multiple ports or sometimes contain as little as two ports. When a packet arrives at one port, it is copied to the other ports so that all segments of the LAN can see all packets. It transmits all data received from each of the network devices present to each and every device, that way the bandwidth from the networks can be shared, but is not as efficient. Networks that use a hub are mostly a star topology, where the hub connects all the devices into the network. A hub is a linking area in video games.
Understanding Computers 13th Edition ch.7 pg.288 </ref>
# The Computer Revolution/Networks/Ways to Minimize Virus Attacks

* Do not open/download/execute files from unknown sources
* Delete spam and emails from unknown sources
* Do not start your computer with a floppy disk in the drive
* Back up files regularly
* Install virus protection software
* Scan your entire system with antivirus software
* Update Protection and Security Systems
* Use firewall software
* Sign up for email alerts through a trusted security company
While setting up a network, whether wired or wireless, you will need to make sure it is secure. Setting up complicated passwords, mixed with letters, numbers and symbols, is one way to prevent unwanted people from accessing any and all information in the network. Encrypting private files or setting the network up as hidden are other ways to prevent access to that information.

## Prevent Virus Attacks

These are just some simple measures you can take to prevent the headache of having to re-format your computer when a virus attacks: change your password periodically to prevent password hacking, backup your programs and data regularly, install virus scanning and cleaning software in each computer, update regularly the virus scanning software from the supplier to detect new viruses, scan the computer regularly with virus scanning software, stay alert with the danger of the open exposure of your files over the internet, switch off automatic processing of e-mail attachments in the Internet e-mail software, scan any downloaded files and e-mail attachments from the Internet for viruses before opening them, scan floppy disks, compact disks and other storage media, especially those of unknown sources, with virus scanning software before use. Also, keep in mind that purchasing anti-virus software is a wise investment if you have valuable data kept on your computer. It should be a routine for you to back up your work as well (save it on another source so you can access it even if your computer crashes or becomes inaccessible).

#### Regular PC check up

It is important to have regular PC checks ups they can help clean out viruses and prevent serious damage to your computer. PC clean ups can help make your computer run faster as well as remove unwanted software. It is also a good way to free up space on your memory. Be aware of free anti-virus as they offer almost no protection for your computer.
# Real Estate Financing and Investing/How To Value an Income Producing Property

There are several rule of thumb methods to arrive at the estimated value of an income producing property. They include:
Purchase price / gross rental income
Example In Mr. Smith`s example from the previous chapter, the gross income multiplier is:
$219,000 / $23,600 = 9.28
A duplex in the similar neighborhood may be valued at "8 times annual gross." Thus, if its annual gross rental income amounts to $23,600, the value would be taken as $188,800 (8 x $23,600). Warning: This approach should be used with caution. Different properties have different operating expenses which must be taken into account in determining the value of a property.
In Mr. Smith`s example, the net income multiplier is:
$219,000 / $18,618 = 11.76
Net operating income (NOI) / purchase price
Example Let us go back to Mr. Smith`s example. The duplex`s capitalization rate is $18,618 / $219,000 = 8.5%. Whether it is over priced or not depends on the rate of the similar type property derived from the market place. Suppose the market rate is 10%. That means the fair market value of the similar duplex is $18,618 / 10% = $186,180. Mr. Smith may be overpaying for this property.
# Real Estate Financing and Investing/Should You Pay Off Your Mortgage Early

Suppose you have decided to refinance your home with a lower fixed rate mortgage. You should consider the term of the loan. Although the standard 30 year mortgage is still very much alive and well, you might want to consider the loan with a shorter term such as a 15 year fixed rate loan.
The overall savings in interest paid to the lender over the life of the 15 year mortgage can be quite substantial, yet the monthly payment is not significantly higher. Recommendation: Even if you decide to stay with your current 30 year mortgage, you might be able to save a bundle by paying off more in each month, treating the 30 year loan as if it were a 15 year loan.
Example: Suppose you currently have a $100,000 30 year fixed rate mortgage at 13 percent. Your monthly payment for principal and interest is $1,106.20. You have decided to refinance your home with a fixed rate loan at 10 percent. You have two options available: 30 year loan at 10 percent vs. 15 year loan at the same rate. Look at Table 3 for comparison regarding monthly payment and total interest over the life of the loan.
Note: In either case, the monthly payment is less than the 13 percent mortgage. Between 30 year and 15 year, however, the monthly payment increases about 22.45% while the savings in total interest payments over the life would be almost 57 percent. From this example, you learn some valuable lessons:
* It was a good decision to refinance your home, since, in either case, you save in your monthly payments ($1,106.20 vs. $877.57 and $1,074.61). In this example, a 3 percent drop in the fixed rate made this possible.
* You would be able to save $122,495 in total interest payments by election of a 15 year loan without increasing your monthly burden.
* Among other things, you will be a 100 percent equity holder in your home within 15 years instead of 30 years.
Table 3. Comparison of 30-Year vs. 15-Year Fixed Rate Mortgage
| | 30-year | 15-year | $ Increase (Decrease) | % Increase (Decrease) |
| Principal | $100,000 | $100,000 | -- | -- |
| Rate | 10% | 10% | -- | -- |
| Monthly Payment | $877.57 | $1074.61 | $197.04 | 22.45% |
| Total Interest | $215,925 | $93,420 | ($122,495) | (56.73%) |
# Real Estate Financing and Investing/Investing In Real Estate is an I.D.E.A.L. Situation

It has often been said that real estate is the I.D.E.A.L. investment. Each of the five letters in IDEAL stands for an advantage to real estate as an investment.
• "I" stands for interest deduction. In the United States, the mortgage interest paid on the first and second residential homes are tax deductible. On the average, real estate is a good hedge against inflation because property values and the income from properties rise to keep pace with inflation. "I" could mean income. Successful real estate investments usually produce an income stream that typically increases over time.
• "D" stands for depreciation. The building on your land depreciates in book value each year and you can deduct this depreciation from your gross income. This is only true for investment property and not residential. This provides a tax shield.
• "E" is for equity buildup. You build equity through repayments of the principal or remaining balance of the loan(s) taken to purchase the property. This equity buildup is like money in the bank. As you amortize a mortgage, the value of your equity investment will steadily rise. In the case of income producing property, this amortization could mean that your tenants help you build your estate.
• "A" is for appreciation. Your property value goes up every year, hopefully. Appreciation can result from inflation or increases in demand for property or improvement to the property . As the income potential is increases, the price that the property can command in the marketplace rises.
• "L" is for leverage. When you buy a house you make a down payment, say, 10 percent and you borrow the balance, say, 90 percent. You get the benefit of all 100 percent even though you put up only 10 percent of your own money. You can maximize return with other people`s money (OPM). The use of mortgage and OPM means that you can use small amounts of cash to gain control of large investments and earn large returns on the cash invested.
Besides I.D.E.A.L., you could add the following advantages of investing in real estate:
• Tax free refinancing. In the United States, mortgage proceeds even from refinancing are not taxable income to you. Therefore, refinancing is a way to recover your cash investment and, in some cases, you profit tax free.
• Pride of ownership. You may find greater personal satisfaction in owning property than stock certificates.
• Investment and consumption. Certain types of real estate, such as land and vacation homes, can serve both as investments and as sources of pleasure through use.