VLSI stands for “very large scale integration”. This is the field which involves packing more and more logic devices into smaller and smaller areas. Thanks to VLSI, circuits that would have taken boardfuls of space can now be put into a small space few millimeters across. Digital VLSI circuits are predominantly CMOS based. Most of the VLSI circuits available in the commercial market nowadays are of the programmable type and are called programmable Logic Device is a whose logic characteristic can be changed and manipulated or stored through programming . The type of PLD is as follows:
·Programmable array logic (PAL)
·Configurable programmable logic devices (CPLD)
·Field programmable gate array ( FPGA)
Adaptive Noise cancelling is a speech-specific filtering technique to suppress additive interference. It is a sensible choice for speech-orientated devices in situations where the designer has no knowledge of the properties of interference that could potentially corrupt the input speech to a point beyond intelligibility. A good example of devices subject to such noise is mobile telephones, where the user may be communicating in a variety of environments. However, constraints appear when implementing a noise-cancelling algorithm on such a portable device, and issues of power consumption and silicon area become prominent
2. Find the least number which when divided by 35,leaves remainder 25,when divided by45,leaves remainder 35 and when divided by 55,leaves remainder 45?
Sol: 3455
Hint: l.c.m of(35,45,55) minus 10
l.c.m is 3465.Hence the answer is 3455.
3. What is the remainder left after dividing 1!+2!+3!+...+100! By 7?
Sol: 5
Hint: 7! Onwards all terms are divisible by 7 as 7 is one of the factor. So there is no remainder left for those terms. i.e. remainder left after dividing 7!+8!+9!+..+100! Is 0.The only part to be consider is=1!+..+6!=873;
The remainder left after dividing 873 by 7 is 5.Hence the remainder is 5.
4. Two identical pack of cards A and B are shuffled thoroughly.
One card is picked from A and shuffled with B. The top card from pack A is turned up. If this is the Queen of hearts, what are the chances that the top card in B will be the King of hearts?
Sol: 52/2703
Hint: There are two cases to be considered.
Case1: King of hearts is drawn from pack A and shuffled with pack B.
Probability of drawing king of hearts from pack A=1/51(as queen of hearts is not to be drawn. Probability of having King of hearts on the top of the pack B=2/53
So, total probability of case 1=(1/51)*(2/53)=2/(51*53)
Case 2: King of hearts is not drawn from pack A
Probability of not drawing king of hearts from pack A=50/51(as queen of hearts is not to be
drawn).Probability of having king of hearts on the top of the pack B=1/53
So total probability, the required probability is=2/(51*53)+50/(51*53)
1. Find the next no. in the series 1, 2 ,4 ,13 ,31 ,62 ,124 ,__
Sol: 253
Hint: This is series of 1,2,4,8,16,32,64,128 with the base 5.
2. Expand RISC
Sol: Reduced Instruction Set Computing.
3. At what time after 4.00p.m. is the minutes hand of a clock
exactly aligned with the hour hand?
Sol: 4:21:49.5
Hint: Assume that x minutes after 4.00pm minute hand exactly aligns with and hour hand.
For every minute, minute hand travels 6 degrees.
Hence, for x minutes it will travel 6*x degrees. For every minute, hour hand travels ½ degrees. Hence for x minutes it will travel x/2 degrees. At 4.00pm the angle between minute hand and hour hand is 120 degrees. Also, after x minutes, minute hand and hour hand are exactly aligned. So the angle with respect to 12 i.e. Vertical plane will be same. Therefore,
Hint: stack overflow. main function calls itself again and again. Each time the function is called its return address is stored in the call stack. Since there is no condition to terminate the function call, the call stack overflows at runtime. So it terminates the program and results in an error.
5. A class of 100 students.24 of them are girls and 32 are not. Which base is used here?
Sol: 6
Hint: Let the base be x. Therefore (x*x + x*0+0)=(2*x+4)+(3*x+2)
A series of steps followed to obtain a database design that allows for efficient access and storage of data in a relational database .These steps reduce data redundancy and the chances of data becoming inconsistent.
A table in a relational database is said to be in normal form if it satisfies certain constraints. Codd’s original work defined three such forms but there are now five generally accepted steps of normalization. The output of the first step is called First Normal Form (1NF); the output of the second step is Second Normal Form (2NF), etc.
First Normal Form eliminates repeating groups by putting each into a separate table and connecting them with a one-to-many relationship
Second Normal Form eliminates functional dependencies on a partial key by putting the fields in a separate table from those that are dependent on the whole key
Third Normal Form eliminates functional dependencies on non-key fields by putting them in a separate table. At this stage, all non-key fields are dependent on the key, the whole key and nothing but the key.
Fourth Normal Form separates independent multi-valued facts stored in one table into separate tables.
Fifth Normal Form breaks out data redundancy that is not covered by any of the previous normal forms.
A unique primary key generated by the RDBMS that is not derived from any data in the database and whose only significance is to act as the primary key.
A surrogate key is frequently a sequential number but doesn't have to be. Having the key independent of all other columns insulates the database relationships from changes in data values or database design and guarantees uniqueness.
Some database designers use surrogate keys religiously regardless of the suitability of other candidate keys However, if a good key already exists, the addition of a surrogate key will merely slow down access, particularly if it is indexed.
Intelligent key
A relational database which depends wholely on one or more other columns in the same table. An intelligent key might be identified for implementation convenience, where there is no good candidate key
For example, if the three-letter initials of a group of people are known to be unique but only their full names are recorded, a three letter acronym for their names (e.g. John Doe Smith -> JDS) would be an intelligent key.
Intelligent keys are a Bad Thing because it is hard to guarantee uniqueness, and if the value on which an intelligent key depends changes then the key must either stay the same, creating an inconsistency within the containing table, or change, requiring changes to all other tables in which it appears as a foreign key The correct solution is to use a surrogate
Partial key
A key which identifies a subset of a set of information itemsand which could narrow the subset to one item if other partial key(s) were combined with it.
Compound key
(Or "multi-part key", "concatenated key") A key which consists of more than one attribute of the body of information (e.g. database "record ") it identifies.
Alternate key
A candidate key which is not selected as a primary key
Unique key
A key which identifies only one body of information out of several.
Primary key
The candidate key selected as being most important for identifying a body of information (an entity, object or record).
Candidate key
One of several possible attributes or combinations of attributes which can be used to uniquely identify a body of information (a "record ").
Super Key
A Set of attributes that uniquely identify a tuple in a relation is called a super key.
Secondary Keys
Keys other than the candidate keys are called the secondary keys.
Foreign Key
A key column in a table that identifies records in a different tbale is called foreign key.
·Sophisticated users: interact with the DBMS using the DML directly. The query processor translates DML commands into commands to the database manager.
·Specialized users: interact with the DBMS in specialized ways:
·CAD
·Expert systems
·Graphical or audio data
·Temporal data
·Naive users: interact with the database through application programs.
The data definition language (DDL) is the language used to define and modify the conceptual scheme of the database.
·Often used to define/modify sub schemes
·The definition of the conceptual scheme (written in the DDL) is compiled into a file called the data dictionary
·The data dictionary is consulted for scheme information whenever data is read or modified
·A separate language called the data storage and definition language is used to access the physical scheme of the database
Data Manipulation Language (DML):
The language used at the conceptual and view levels to retrieve, insert, delete and modify information stored in the database
Query
A request for information retrieval. Example (in English): List all customers who have an account balance over $500
Query language
The part of the DML used for retrieving information
The terms query language and data manipulation language are often used interchangeably.
Example: SQL is a DML, but is usually called a query language.
DML's are classified by the kind of query language they include:
·Procedural DML's require the user to specify what data is needed and to provide an algorithm for getting the data. The algorithm is written in query language.
Examples: SQL, Quell
·Nonprocedural DML's require only that the user specify what data is needed
Examples: Data log, QBE
Notes:
·Like the distinction between procedural programming languages (C, C++, Ada) and nonprocedural languages (Prolog)
·DDL's manipulate schemes, while DML's manipulate instances