exercises1

Exercise6-1Square Root VIObjective:To use the Case structure.Complete the following steps to build a VI that checks whether a number ispositive.If it is,the VI calculates the square root of the number.Otherwise,the VI returns an error message.Caution Do not run this VI continuously.Front Panel1.Open a new VI and build the following front panel.Block Diagram2.Build the following block diagram.a.Place a Case structure located on the Functions»Structures palette.b.Click the decrement and increment arrow buttons to select theFALSE case.c.Place the Greater or Equal to0?function located on the Functions»Comparison palette.This function returns TRUE if Numeric isgreater than or equal to0.d.Right-click the numeric constant and select Format&Precisionfrom the shortcut menu.Set Digits of Precision to1,select FloatingPoint Notation,and click the OK button.e.Place the One Button Dialog function located on the Functions»Time&Dialog palette.This function displays a dialog box thatcontains the message Error...Negative Number.f.Right-click the message terminal of the One Button Dialog function,select Create»Constant from the shortcut menu,typeError...Negative Number,and press the<Enter>key.Refer toLesson7,Strings and File I/O,for more information about strings.g.Select the TRUE case and place the Square Root function located onthe Functions»Numeric palette,as shown in the following blockdiagram.This function returns the square root of Numeric.3.Save the VI as Square Root.vi.4.Display the front panel and run the VI.If Numeric is positive,the VI executes the TRUE case and returnsthe square root of Numeric.If Numeric is negative,the VI executes the FALSE case,returns–99999.0,and displays a dialog box with the message Error...Negative Number.5.Close the VI.End of Exercise6-1Exercise6-2Temperature Control VIObjective:To use the Case structure.Complete the following steps to build a VI that detects when a temperatureis out of range.If the temperature exceeds the limit,an LED turns on and abeep sounds.Front Panel1.Open the Temperature Running Average VI,which you built inExercise4-5.2.Modify the front panel as follows.3.Right-click the chart display and select Visible Items»Digital Displayfrom the shortcut menu to display the digital values.4.Save the VI as Temperature Control.vi.Block Diagram5.Modify the block diagram as follows.The FALSE case of the Casestructure is empty.a.Place the Greater?function located on the Functions»Comparisonpalette.This function returns TRUE if the temperature exceeds HighLimit.Otherwise,the function returns FALSE.b.Place the Beep VI located on the Functions»Graphics&Sound»Sound palette.This VI sounds a beep if the selector terminalof the Case structure receives TRUE.c.(Macintosh)Provide values for the Beep VI input terminals.6.Save the VI,because you will use this VI later in the course.7.Display the front panel,enter80in High Limit,and run the VI.If the VI returns a temperature greater than High Limit,Warning turnson,the VI executes the TRUE case,and a beep sounds.If thetemperature is less than High Limit,Warning turns off,the VI executesthe FALSE case,and no beep sounds.8.Close the VI.End of Exercise6-2Exercise6-3Time to Match VIObjective:To use the Sequence structure.Complete the following steps to build a VI that computes the time it takes togenerate a random number that matches a number you specify.Front Panel1.Open the Auto Match VI,which you built in Exercise4-3.2.Modify the front panel as follows.a.Change Number to Match,Current Number,and#of iterationsto I32representation.b.Change Time to Match to DBL representation and3digits ofprecision.3.Save the VI as Time to Match.vi.Block Diagram4.Modify the block diagram as follows.a.Place a Sequence structure located on the Functions»Structurespalette.b.Right-click the structure border and select Add Frame After fromthe shortcut menu to add a frame.c.Place the Tick Count(ms)function located on the Functions»Time&Dialog palette.This function reads the current value of theoperating system clock and returns the value in milliseconds.5.Save the VI.6.Display the front panel,enter a number in Number to Match,and runthe VI.In frame0,the VI executes the While Loop while Current Numberdoes not match Number to Match.In frame1,the Tick Count(ms)function reads the operating system clock.The VI subtracts the newvalue from the initial time read and returns the elapsed time in seconds.Note If Time to Match is always0.000,the VI might be running too quickly.Either run the VI with execution highlighting enabled or increase the numeric constant wired to the Multiply function in frame0to a large value,such as1000000.7.Close the VI.End of Exercise6-3Exercise6-4Formula Node Exercise VIObjective:To use the Formula Node.Complete the following steps to build a VI that uses the Formula Node toperform a complex mathematical operation and graphs the results.Front Panel1.Open a new VI and build the following front panel.Block Diagram2.Build the following block diagram.a.Place the Formula Node located on the Functions»Structurespalette.b.Create the x input terminal by right-clicking the left border andselecting Add Input from the shortcut menu.c.Create the y and a output terminals by right-clicking the right borderand selecting Add Output from the shortcut menu.Y ou must createoutput terminals for temporary variables like a.Note When you create an input or output terminal,you must use a variable name thatexactly matches the one in the equation.V ariable names are case sensitive.d.Type the following equations in the Formula Node,where**is theexponentiation operator.Refer to the LabVIEW Help for moreinformation about syntax for the Formula Node.a = tanh(x) + cos(x);y = a**3 + a;3.Save the VI as Formula Node Exercise.vi.4.Display the front panel and run the VI.The graph displays the plot of theequation y=f(x)3+f(x),where f(x)=tanh(x)+cos(x).During each iteration,the VI divides the iteration terminal value by15.0.The quotient is wired to the Formula Node,which calculates thefunction value.The VI plots the array as a graph.5.Close the VI.End of Exercise6-4Additional Exercises6-5Build a VI that uses the Formula Node to calculate the followingequations:y1=x3+x2+5y2=mx+bUse only one Formula Node for both equations and use a semicolon(;)after each equation in the node.Save the VI as Equations.vi.6-6Build a VI that functions like a calculator.On the front panel,usedigital controls to input two numbers and a digital indicator todisplay the result of the operation(Add,Subtract,Divide,orMultiply)that the VI performs on the two e a slidecontrol to specify the operation to perform.Save the VI as Calculator.vi.6-7Modify the Square Root VI,which you built in Exercise6-1,sothe VI performs all calculations and condition checking using theFormula Node.Save the VI as Square Root 2.vi.6-8Build a VI that has two inputs,Threshold and Input Array,and oneoutput,Output Array.Output Array contains values from Input ChallengeArray that are greater than Threshold.Save the VI as Array Over Threshold.vi.Create another VI that generates an array of random numbersbetween0and1and uses the Array Over Threshold VI to output anarray with the values greater than0.5.Save the VI as Using Array Over Threshold.vi.。

Exercises 11.List significant differrences between a file-processing system and a DBMS.2.What are the advantages and disadvantages of database?3.Explain the difference between physical and logical data independence.Discuss the ANSI-SPARC three-level architecture.4. What is a data model? Discuss the main types of data models.An integrated collection of concepts for describing and manipulating data, relationships between data, and constraints on the data in an organization. (See Section 2.3.)Object-based data models such as the Entity–Relationship model (see Section 2.3.1). Record-based data models such as the relational data model, network data model, and hierarchical data model (see Section 2.3.2). Physical data models describe how data is stored in the computer (see Section 2.3.3).Answer:•Physical data independence is the ability to modify the physical scheme without making itnecessary to rewrite application programs. Such modifications include changing from unblocked to blocked record storage, or from sequential to random access files.•Logical data independence is the ability to modify the conceptual scheme without making itnecessary to rewrite application programs. Such a modification might be adding a field to a record; an application pr ogram’s view hides this change from the program.Exercises 21.The following tables form part of a database held in a relational DBMS:Hotel (hotelNo, hotelName, city)Room (roomNo, hotelNo, type, price)Booking (hotelNo, guestNo, dateFrom, dateTo, roomNo)Guest (guestNo, guestName, guestAddress)where Hotel contains hotel details and hotelNo is the primary key;Room contains room details for each hotel and (roomNo, hotelNo) forms the primary key;Booking contains details of the bookings and (hotelNo, guestNo, dateFrom) forms the primary key;and Guest contains guest details and guestNo is the primary key.Identify the foreign keys in this schema. Explain how the entity and referential integrity rules apply to these relations.For each relation, the primary key must not contain any nulls.Room is related to Hotel through the attribute hotelNo. Therefore, the hotelNo in Room is FK，and should either be null or contain the number of an existing hotel in the Hotel relation. In this case study, it would probably be unacceptable to have a hotelNo in Room with a null value.Booking is related to Hotel through the attribute hotelNo. Therefore, the hotelNo in Booking is FK，and should either be null or contain the number of an existing hotel in the Hotel relation. However, because hotelNo is also part of the primary key, a null value for this attribute would be unacceptable.Similarly for guestNo. Booking is also related to Room through the attribute roomNo,(guestNo,roomNo) in booking is FK reference Room. guestNo in booking is FK reference Guest.Describe the relations that would be produced by the following relational algebra operations:(a)∏hotelNo (σprice> 50 (Room) )This will produce a relation with a single attribute (hotelNo) giving the number of those hotelswith a room price greater than £50.(b)σHotel.hotelNo=Room.hotelNo(Hotel⨯Room)This will produce a join of the Hotel and Room relations containing all the attributes of bothHotel and Room (there will be two copies of the hotelNo attribute). Essentially this willproduce a relation containing all rooms at all hotels.Produce some sample tables for these relations that observe the relational integrity rules. Suggest some enterprise constraints that would be appropriate for this schema.Student should provide some sample tables, observing entity and referential integrity. In particular, ensure the uniqueness for the composite primary keys of the Room and Booking tables.Some enterprise constraints may be:•There can be no two bookings for the same room in the same hotel on the same day.•For the Booking relation, dateFrom must be before dateTo.•Room price must be greater than 0 and less than £200.3.Consider the relational database of Figure 1,employee (person-name, street, city)works (person-name, company-name, salary)company (company-name, city)manages (person-name, manager-name)Figure 1. Relational databasewhere the primary keys are underlined.Give an expression in the relational algebra to express each of the following queries:a.Find the names of all employees who work for First Bank Corporation.b. Find the names, street address, and cities of residence of all employees whowork for First Bank Corporation and earn more than $10,000 per annum.c. Find the names of all employees in this database who live in the same cityas the company for which they work.Answer:a. Πperson-name (σcompany-name = “First Bank Corporation” (works))b. Πperson-name, street, city(σ(company-name = “First Bank Corporation” ∧salary > 10000)works ×employee)e. Πperson-name (employee ×works×company)。

(P40)The market is huge with China to buy 2922 large passenger jets before the year of 2028, which is almost $400 billion.
Exercises 1:
1. Explain these words and expressions through their context or with the help of adictionary.(p12)
• Gestures are interpreted differently from one country to another. Try to discuss the meaning of the following gestures in different countries.
提示：完成任务7.(可用PPT形式或word 文档形式呈现)
Calling someone towards you by repeatedly curling your index finger is a seductive gesture in many Hollywood films, but in Philippines it's a method of communication only considered appropriate to use on dogs.
Check-up 核查:
1. 请两位同学示范朗读Text B 选段； 2. 展示两位同学任务11的作业； 3. 复习上节课重点词汇和句子。
Review 复习:
Text B以及Text A(p4-6)涉及听写单词、句子：
make a deal, pick…up…, business reception, recommend, register, alert, impression, impressive , due to,

Unit Two1.Of all American cities, San Francisco is considered by many to be ___ far themost beautiful.A. soB. byC. thisD. that2. Francis Chichester is ___ one of the greatest adventurers the world has ever known.A. undoubtedlyB. doubtfulC. doubtfullyD. doubt3. She is young and ___, but she is good at learning.A. experienceB. inexperienceC. inexperiencedD. experienced4. We’ll do our best to help those ___ people.A. fortuneB. misfortuneC. unfortunateD. fortunate5. They ___ the war, although it cost them millions of lives.A. wonB. beatC. defeatedD. conquered6. They aren’t doing well in school, ___ their intelligence.A. thoughB. althoughC. in spite ofD. despite of7. This is ___ we should always keep in mind.A. thatB. whatC. whyD. when8. After succeeding ___ sailing round Cape Horn, Chichester sent a radio message to London.A. atB. onC. inD. of9. He gave ___ his seat on the bus to an old woman standing nearby.A. outB. offC. overD. up10. Though she is nearly 65, Mary doesn’t want to ___.A. retireB. retellC. repeatD. restore11. The boy ___ his fear of dark and walked alone in the woods at night.A. contactedB. conqueredC. contentedD. covered12. I can’t help ___ that it was a mistake to let him go.A. to thinkB. thinkingC. thinkD. of thinking13. His classmates tried to dissuade him ___ swimming across the lake, but he did not listen.A. ofB. fromC. intoD. out14. Payment may be made in any of the ___ ways: by cash, by cheque or by credit card.A. followedB. followingC. followD. to follow15. Tom invented a(n) ___ to make the door shut by itself.A. adviceB. deviceC. serviceD. divorce16. The boat turned ___, throwing the boys into the water.A. overB. offC. outD. on17. Chichester had done what he wanted to ___ in his life.A. accomplishB. completeC. finishD. compete18. It is said that these attacks were carried ___ by terrorists.A. awayB. out ofC. outD. of19. This was more than twice the distance anyone had ___ sailed alone.A. obviouslyB. obviousC. previouslyD. previous20. It had taken him nine months, of ___ the sailing time was 226 days.A. thatB. the nine monthsC. the timeD. whichKeys: 1-5: BACCA 6-10: CBCDA 11-15: BBBBB 16-20: AACCD1.所有美国城市,旧金山被许多人认为是迄今为止最美丽。