2. Literature review
An early vending machine is invented by Hero of Alexandria, a first-century engineer and mathematician [1]. In 1876, Simeon Denham built a vending machine dispensing stamps called “the first fully automatic vending machine”. A modern coin-operated vending machine was first introduced in London in 1883 by Percival Everitt. After that, vending machines have become well-known and been widely used in England.
The following is details about background knowledge related to the design of the vending machine.
2.1 Truth Tables [2]
Figure 2.1: An example of truth table.
Truth tables are a kind of table for describing the set of result for each alternative set of inputs. Using the truth table will help designers to write Boolean expressions more easily. An example of the truth table can be found at Figure 2.3. The output V will be one if two or three of the inputs are one.
2.2 Gates [2]
A gate is a primitive building box which describes Boolean expressions. Standard logic gates are gates for the logic operators AND, OR and NOT (Figure 2.2). These gates are formed from transistor switches. Every Boolean expression can be implemented by wiring a combination of gates together. The AND operator is a “multiply” in Boolean expressions, OR operator is a “plus” or “+”, and NOT is an “inverse” or “~”. The Boolean expression V = ~ (((A*B) + (~C)) * D) can be implemented as Figure 2.3.
Figure 2.2: Standard logic gates. Figure 2.3: An implemented of V = ~ (((A*B) + (~C)) * D)
2.3 A Digital Clock Signal
Figure 2.4 [2]: A Digital Clock Signal
Figure 2.4 shows A Digital clock signal used for synchronize different part of circuit. It has only two values, high and low. A word, “clock” used in this report means the...
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...bove, it can be concluded that the designed vending machine is able to provide a function for the buyer to purchase more than one product at a time. In contrast, current vending machines sell only one. If the buyer wants to purchase more than one product, he needs to put the change back into the machine before the next purchasing order. This is time-wasting. The designed vending machine can solve this problem. After testing, the machine seems to save the purchasing time when a customer wants to buy more than one product from the machine. In addition, the vending machine can operate 24 hours a day, so the buyer can purchase products even at midnight when all nearby retailers are already closed. Also, using a vending machine can save the cost of hiring workers and save more space since it is smaller than a block of retail store and do not need to be observed by humans.
Joshua Klein was at a cocktail party with his friends when one was complaining about the crows in their yard. Joshua mentioned that they should train them to do something useful, and the friend responded that it was impossible. This is what brought Klein to his idea of making a vending machine for crows. Klein studied crows and found that they adapt a lot to live in our world. He figured he would make something useful and beneficial for both the birds and us. After spending years reading about crows, Klein made his vending machine.
(Sketch 24) Show logical notation that expresses following statement: If one dice shows an even number of spots and the second dice show an odd number of spots, then the total for the pair is less than or equal to 9.
Lastly, to wrap up, after living for a short 49 years, Boole is buried in the Church of Ireland. Boolean algebra and Boolean Logic are still around to this day and probably will be for many, many more years.
In “Hooked on ‘Caramel-Colored Gold,” Melody Nelson claims “Despite the increased awareness of the benefits of good nutrition, we are a nation hooked on junk food, and many school administrators are taking advantage of the situation ” (par. 3). Nelson propose a ban on vending machines in schools because junk food is unhealthy for children, and they risk future health problems. I agree with Melody Nelson and believe that vending machines should be banned from school campuses, because they sell unhealthy food, they cause more money to schools for hiring extra custodians, and they are affecting children learning abilities.
For the above expression, logic implementation needs four peres gates and anly ane Feynman gate. Following fig.5 shows 2*2 reversible logic multiplier implantation.
It was pure joy to learn how the Boolean logic makes computers work. In my undergraduate studies I took up courses in Software Engineering, Computer Networks, Data Structures, JAVA, Operating Systems, Computer Graphics, Design and Analysis of Algorithms, Database Management, Web Technology and Mobile Application Development. Practical application aspects were introduced to me through laboratories corresponding to the subjects.... ... middle of paper ...
Brain, Marshall. “How Microprocessors Work.” HowStuffWorks. Discovery Communications LLC, 14 Feb. 2011. Web. 13 Feb. 2011. .
As the author of the article concedes, the online shopping has flourished in the past years. Many customer have seen the advantages of e-commerce in the ways of time and money saving. Whit a simple click on the keyboard the goods are uploaded in a virtual cart and from there are delivered to the customer address. Also, the online stores have the opportunity to create a customer database and a customer profile. The customers receive periodic reminders of the new offers and sales via email or mobile phone messages. In the meantime, many classic stores have struggled to maintain the business keep up. According to the article, the brick and mortar stores will implement new features that conduct customers to an easy and pleasant shopping. For instance, the retailers will use the customer mobile phone as a concierge application. The customer will be informed about latest products and their availability. Furthermore, the customer will have the possibility to track needed items inside the store with the help of store mapping and products locations. If the customer will change the shopping list, the app will provide the route to the new item. Also, when a customer will passing a store the app will remind the last customer visit into the store and
logic is expressed in terms of relations, represented as facts and rules. A computation is initiated by
In 500 B.C. the abacus was first used by the Babylonians as an aid to simple arithmetic. In 1623 Wihelm Schickard (1592 - 1635) invented a "Calculating Clock". This mechanical machine could add and subtract up to 6 digit numbers, and warned of an overflow by ringing a bell. J. H. Mueller comes up with the idea of the "difference engine", in 1786. This calculator could tabulate values of a polynomial. Muellers attempt to raise funds fails and the project was forgotten. Scheutz and his son Edward produced a 3rd order difference engine with a printer in 1843 and their government agreed to fund their next project.
Some time between 1041 and 1048, Bi Sheng created the very first device capable of moving type in China. This movable type method used single letterforms to recreate a document in a less painstakingly manner. In 1450, a German printer, by the name of Johannes Gutenberg, created an improved mechanical printing press. Gutenberg’s printing press made printing multiple books easier with its ability to mass-produce. Gutenberg, whom had been a goldsmith for some time, took what he knew an...
punched in them, appropriately called “punchcards”. His inventions were failures for the most part because of the lack of precision machining techniques used at the time and the lack of demand for such a device (Soma, 46).
Words that have to do with logic like and, or, not are given symbols like &, V, or an upside down L reversed. The Letters X, Y, Z and so on are commonly used as variables and P, Q, R are used as predicates, properties or relations.
Thousands of years ago calculations were done using people’s fingers and pebbles that were found just lying around. Technology has transformed so much that today the most complicated computations are done within seconds. Human dependency on computers is increasing everyday. Just think how hard it would be to live a week without a computer. We owe the advancements of computers and other such electronic devices to the intelligence of men of the past.
The fist computer, known as the abacus, was made of wood and parallel wires on which beads were strung. Arithmetic operations were performed when the beads were moved along the wire according to “programming” rules that had to be memorized by the user (Soma, 14). The second earliest computer, invented by Blaise Pascal in 1694, was a “digital calculating machine.” Pascal designed this first known digital computer to help his father, who was a tax collector. Pascal’s computer could only add numbers, and they had to be entered by turning dials (Soma, 32). It required a manual process like its ancestor, the abacus. Automation was introduced in the early 1800’s by a mathematics professor named Charles Babbage. He created an automatic calculation machine that was steam powered and stored up to 1000 50-digit numbers. Unlike its two earliest ancestors, Babbage’s invention was able to perform various operations. It relied on cards with holes punched in them, which are called “punch cards.” These cards carried out the programming and storing operations for the machine. Unluckily, Babbage’s creation flopped due to the lack of mechanical precision and the lack of demand for the product (Soma, 46). The machine could not operate efficiently because technology was t adequate to make the machine operate efficiently Computer interest dwindled for many years, and it wasn’t until the mid-1800’s that people became interested in them once again.