Author Archives: Geneva Sibanda

About Geneva Sibanda

I assist companies in the Areas of Network Infrastructure Design and Implementation: (from Windows Active Directory Security, networking, etc.).

SimpliVity Data Virtualization Platform Architecture

Simplify and scale your data center infrastructure through SimpliVity data virtualization platform using hyper-convergence.

SimpliVity is accelerating its technology leadership in hyper-converged infrastructure space, definitely a killer technology and a major disruptive solution in the evolution of converged infrastructure. With SimpliVity, the hyper-converged technologies is a really change the game.

Are you considering a move to public cloud?

For a lot of companies the cloud does make sense. From a cost perspective, design is a few configurations steps, installation less than an hour, the ease to use the SimpliVity hyperconverged solution reduce the management task essential to the VM level, operational costs are lower. You scale-out fast and non-disruptive.

To truly simplify IT in post-virtualization data centers, the “data problem” must be addressed.

SimpliVity’s Data Virtualization Platform delivered on hyperconverged infrastructure simplifies IT and operations, and uniquely enables data mobility and efficiency. SimpliVity reduces IOPS, capacity and bandwidth requirements, and provides native data protection, eliminating additional hardware and tools—resulting in a 300% TCO savings.

OmniStack with Cisco Unified Computing System

SimpliVity’s OmniStack is the industry’s first and only globally-federated and hyperconverged solution that supports Cisco Unified Computing Systems. Designed and optimized for the virtual environment, each OmniStack solution delivers server, storage, and networking services, as well as dramatic improvements to the management, protection, and performance of virtualized workloads—all at a fraction of the cost and extreme reduction in complexity compared to today’s traditional infrastructure technologies

To be continued…

Figthing Back Against: Ransomware

Understanding: Ransomware and how to protect against ransomware attacks.

Ransomware is a type of malware that holds your computer hostage.

Prevention is good, Protection is better, Back up is a must

Ransomware is a malicious software virus that infects a computer, network or data. During the infection, your computer will either be locked or your data encrypted, held hostage, and the only way you can regain access is by paying a “ransom”. Ransom is typically demanded in Bitcoin, a largely anonymous currency, which is often used in cyber black markets. Ransomware is classified as a “denial of access” attack, denying the victim access to the electronic device or data stored on the device until a ransom is paid.

Distributing ransomware is a criminal activity, and even though the technology it utilises is quite sophisticated, the prevalence of ransomware hinges on the exploitation of the human element – as do most criminal activities. Malware such as ransomware is not a new phenomenon, but it has become increasingly widespread and invasive in recent years.

Data backup is absolutely essential

Who is targeted by ransomware, Business and Larger Organisation are all exposed at the same risks as individual home users ransomware doesn’t discriminate.

There are four ways that ransomware could infect your computer:

1. Spam Emails

Firstly spam emails can be used to mislead unsuspecting users into opening infected email or email attachment, and it will activate upon installation.

2. Infected removable drives

Secondly it spreads by infected removable drives, the ransomware is created to install automatically when the drive is plugged in and can spread through a network to other machines.

3. Trojan Horse

Thirdly, is using a Trojan horse. The malware attaches to a legitimate application often downloaded from a questionable.

4. Compromised Webpages

Lastly, compromised webpages, some websites can be infected by ransomware by simple browsing to them without clicking to anything can exposed your computer, if attacked immediately disconnect your computer from the network or internet, format all infected drives and recover your data from clean resent backup.

How to protect your PC from ransomware attacks

Remember, Prevention is good, Protection is better, Back up is a must!

It’s always beneficial to plan for the worst case scenario. We can assist you with tested and practical online backup solution – Starting From R100 p/m. You can protect data Up to (4GB).

COS2626: Assignment 02: Semester 2

COS2626: Assignment 02: Semester 2: October 2015

Question 1

The following questions are based on wireless networking.

1.1 Define the term wireless spectrum.

The wireless spectrum is a continuum of the electromagnetic waves used for data and voice communication.

1.2 Describe the CHARACTERISTICS wireless transmissions have in common with wired transmissions.

Use of the same layer 3 and higher protocols.
Just as with wired signals, wireless signals originate from electrical current traveling along a conductor.

1.3 Describe the DIFFERENCE between wireless and wired transmissions.

The nature of the atmosphere makes wireless transmissions vastly different from wired transmission. Because the air provides no fixed path for signals to follow, signals travel without guidance. This is in contrast to guided media that do provide a fixed signal path.

1.4 Explain why wireless networks are not laid out using the same topologies as wired networks.

Because they are not bound by cabling paths between nodes and connectivity devices, wireless networks, are not laid out the same topologies as wired networks.

1.5 Which WLAN (Wireless Local Area Network) architecture is depicted in the following diagram?

An ad hoc WLAN. In an ad hoc WLAN, wireless nodes or stations, transmit directly to each other via wireless NICS without an intervening connectivity device.

1.6 Explain the ADVANTAGE of having WLANs support the same protocols (for example, TCP/IP) and operating systems (for example, UNIX, Linux, or Windows) as wired LANs.

This compatibility ensures that wireless and wired transimission methods can be integrated on the same network.

1.7 Describe the use of CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance) to access a shared medium.

Note the significance of using ACK packets to verify every transmission.

802.11 standards specify the use of CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance) to access a shared medium.

Using CSMA/CA, before a station begins to send data on an 802.11 network, it checks for existing wireless transmission. If the source node detects no transmission activity an the network, it waits a brief, random amount of time, and then sends its transmission. If the source does detect activity, it waits a brief period of time before checking the channel again. The destination node receives the transmission and, after verifying its accuracy, issues an acknowledgment (ACK) packet to the source. If the source receives this acknowledgment, it assumes the transmission was properly completed. However, interference or other transmissions on the network could impede this exchange. If, after transmitting a message, the source node fails to receive acknowledgment from the destination node, it assumes its transmission did not arrive properly, and it begins the CSMA/CA process anew.

Question 2

Match each statement with the correct term below. Write only the number of statement and the corresponding term, e.g. 2.1-a

2.1 Displays TCP (Transmission Control Protocol) /IP (Internet Protocol) statistics and details about TCP/IP components and connections on a host.
2.2 This command provides not only the host’s IP address, but also the primary DNS server name and address that holds the record for this name.
2.3 Useful only on networks that run Windows-based operating systems and NetBIOS.
2.4 Both in its simplest form and when used with one or more of its simplest switches, this utility can provide more detailed information than nslookup.
2.5 The TCP/IP administration utility for use with Windows operating systems.
2.6 Allows you to view a host’s routing table.
2.7 Used if an administrator already know a host’s name and wants to learn its IP address.
2.8 The TCP/IP configuration and management utility used on UNIX and Linux systems.
2.9 Uses ICMP (Internet Control Message protocol) ECHO requests to trace the path from one networked node to another, identifying all intermediate hops between the two nodes.

 

a. ipconfig utility
b. ifconfig utility
c. netstat utility
d. nbstat utility
e. host utility
f. dig utility
g. nslookup utility
h. route utility
i traceroute utility

Solution:

2.1 C
2.2 g or f
2.3 d
2.4 f or g
2.5 a
2.6 h
2.7 e
2.8 b
2.9 i

Question 3

Study the following diagram depicting the elements of virtualization. Identify components ‘A’, ‘B’ and ‘C’ respectively.

A: Hypervisor
B: Virtual machines (Geusts)
C: Physical computer (host)

Question 4

Study the following diagram depicting a VPN (Virtual Private Network) connection and answer the questions that follow.

4.1 Define a VPN.

VPNs are wide area networks that are logically defined over public transmission systems.

4.2 What are TWO important considerations when designing a VPN?

Interoperability and security.

4.3 What does the letter ‘A’ in the diagram represent?

Tunnel

Question 5

Name and discuss FIVE factors that cloud computing is distinguished by.

1. Self-service and on demand – Services, applications and storage in a cloud are available to users at anytime, upon the users request.
2. Elastic – The term elastic in cloud computing means that services and storage capacity can be quickly and dynamically – sometimes even automatically – scaled up or down.
3. Support for multiple platforms – Clients of all types, including smartphones, laptops. desktops, thin clients and tablet computers can access services, application and storage in a cloud, no matter what operating system they run or where they are located, as long as they have a network connection.
4. Resources pooling and consolidation – In the cloud, as on host computers that contain multiple virtual machines, resources such as disk space, applications and services are consolidated. That means one cloud computing provider can host hundreds of web sites for hundreds of different customers on just a few servers.
5. Metered services – Whether the cloud provides applications, desktops, storage, or a service, its use is measured. A service provider may limit or charge by the amount of bandwidth, processing power, storage space, or client connections available to customers.

Question 6

The following questions are based on security policies.

6.1 Define a security policy.

A security policy identifies your security goals, risks, levels of authority, designated security coordinator and team members, responsibilities for each team member and responsibilities for each employee.

6.2 Name THREE typical goals for security policies.

Ensure that authorised users have appropriate access to the resources they need.
Prevent unauthorised users from gaining access to the network, systems, programs, or data.
Prevent accidental damage to hardware or software.

6.3 Name FOUR possible subheadings for the policy outline.

Password policy, software installation policy, network access policy, e-mail use policy etc.

6.4 A security policy should define what confidential means to the organization. Define term confidential.

In general, information is confidential if it could be used by other parties to impair an organization’s functioning, decrease customer’s confidence, cause a financial loss, damage an organization’s status or give a significant advantage to a competitor.

Question 7

7.1 Define the term backup

A backup is a copy of data or program files created for archiving or safekeeping.

7.2 Define the term optical media and provide examples.

Optical media is a type of media capable of storing digitised data and that uses a laser to write data to it and read date from it. Examples of optical media include all type of CDs, DVDs amd Blu-Ray discs.

7.3 Name THREE DISADVANTAGES of optical media.

1. Because of their modest storage capacity, recordable DVDs and BLu-ray discs may be an adequate solution for home or small office network, but they are not sufficient for enterprise networks.
2. Another disadvantage to using optical media for backups is that writing data to them takes longer than saving data to some other types media, such as tapes or disk drives, or to another location on the network.
3. In addition, using optical media requires more human intervention than other backup methods.

7.4 Describe how tape backup might be implemented on both small and large networks.

On a relatively small network, stand-alone tape drives might be attached to each server. On a large network, one large, centralized tape backup device might manage all of the subsystems’ backups.

7.5 Describe how to perform network backups if an organization does not have a WAN or a high-end storage solution.

If your organization does not have a WAN or a high-end storage solution, you might consider online backups. An online backup, or cloud backup, saves data across the internet to another company’s storage array. Usually, online backup requires you to install their client software. You also need a (preferably high-speed) connection to the internet.

7.6 Describe the Grandfather-Father-Son backup rotation scheme.

When planning your backup strategy, you can choose from several standard backup rotation schemes. The most popular of these schemes, called Grandfather-Father-Son uses daily (son), weekly (father) and monthly (grandfather) backup sets. Three types of backups are performed each month: daily incremental (every Monday through Thursday), weekly full (every Friday) and monthly full (last day of the month).

COS1521: Second Semester: ASSIGNMENT 02 – 2016

Due date: 28 September 2016
Study material: (1) F&M: chapters 5–14, but excluding chapter 12
(2) Tutorial Letter 102: Part I: units 5–14

Please read the relevant study material in F&M and Tutorial Letter 102 before you begin this assignment. See more information about Tutorial Letter 102 in section 2.3 of this tutorial letter.

Submission procedure: Via myUnisa (see section 8.4)

Contribution to semester mark: 60%

Unique assignment number: 700624

This assignment is compulsory: the mark you obtain for this assignment contributes to your semester mark.

  •  Each multiple-choice question has four possible answers. Select the alternative you consider to be the most appropriate.
  • Submit your assignment via myUnisa by the due date. Do not be concerned if myUnisa is down on the due date. If this happens, we are notified about the situation and will take this type of delay into consideration. Try to resubmit the assignment as soon as myUnisa is up again.
  • The mark that you achieve out of a possible 50 marks will be converted to a percentage and will contribute 60% towards your semester mark.

Second semester: Assignment 02

QUESTION 1

A computer uses memory-mapped I/O addressing. The address bus uses 7 lines (7 bits). If memory is made up of 80 words, how many four-register controllers can be accessed by the computer?

1. 12
2. 16
3. 48
4. 60

ANS: 1

Page reference in F&M: 115; 119

QUESTION 2

In the fetch stage of the machine cycle used by the CPU, …

1. instructions are decoded by the control unit.
2. the contents of two input registers are added.
3. the address of the instruction to be copied is held in the program counter register.
4. the task order is sent to a component in the CPU.

ANS: 3

Page reference in F&M: 121

QUESTION 3

Which one of the following statements describes a property of RISC computer architecture?

1. A small set of instructions execute a minimum number of simple operations.
2. A complex instruction is transformed into a set of simple operations and then executed by the CPU.
3. It is easier than other designs because there is a single instruction for both simple and complex tasks.
4. Micromemory holds the set of operations for each complex instruction in the instruction set.

ANS: 1

Page reference in F&M: 124

QUESTION 4

There are four basic network topologies. Which network topology has the following advantage and disadvantage?

Advantage: Each connection can carry its own data load.
Disadvantage: A large amount of cabling and a large number of input/output ports are required.

1. Mesh
2. Star
3. Bus
4. Ring

ANS: 1

Page reference in F&M: 147

QUESTION 5

Which of the following is a form of complex network operated by a service provider?

1. A backbone
2. A LAN
3. A hub
4. A workstation

ANS: 1

Page reference in F&M: 149

QUESTION 6

According to F&M, how many layers does the TCP/IP protocol suite have?

1. 3
2. 4
3. 5
4. 6

ANS: 3

Page reference in F&M: 151, 152

QUESTION 7

Transport layer protocols have been designed for the TCP/IP protocol suite. Which one of the following statements regarding the user datagram protocol (UDP) is not true?

1. It is also known as a connection protocol.
2. It is one of the three transport layer protocols.
3. It is simple and fast.
4. It does not provide a logical connection between packets belonging to a single message.

ANS: 1

Page reference in F&M: 157

QUESTION 8

There are several layers in a TCP/IP protocol suite. What is the physical layer responsible for?

1. Provision of services to the users
2. Node-to-node delivery of frames
3. The movements of individual bits from one node to the next
4. The logical delivery of a message between client and server processes

ANS: 3

Page reference in F&M: 163

QUESTION 9

Documents on the WWW can be grouped into categories. Which type of document is created by a web server whenever a browser requests a document?

1. Static
2. Dynamic
3. Active
4. Hanging

ANS: 2

Page reference in F&M: 177

QUESTION 10

Which one of the following statements regarding the evolution of computer operating systems and hardware is not true?

1. Batch operating systems were designed in the 1950s to control mainframe computers.
2. In the 1950s computers used punched cards for input.
3. Multiprogramming and time-sharing required the operating system to do scheduling.
4. Parallel operating systems required one CPU on one computer when they were first used.

ANS: 4

Page reference in F&M: 189, 190

QUESTION 11

An operating system (OS) can be programmed in such way that its higher layers can be changed without affecting its lower layers. This property refers to the … of the OS.

1. extensibility
2. reliability
3. compatibility
4. portability

ANS: 1

Page reference in F&M: 206

QUESTION 12

In multiprogramming, more than one program is in memory at the same time. Which one of the following is not a memory management technique during multiprogramming?

1. Demand partitioning
2. Demand segmentation
3. Partitioning
4. Demand paging

ANS: 1

Page reference in F&M: 192-196

QUESTION 13

In paging, the memory is divided into equal-sized sections called …

1. segments.
2. threads.
3. frames.
4. pages.

ANS: 3

Page reference in F&M: 194

QUESTION 14

Modern operating systems use three different terms that refer to a set of instructions: program, job and process.
Which of the following states are applicable to a process?

1. Ready, running and terminate
2. Waiting, running and terminate
3. Hold, ready and running
4. Ready, waiting and running

ANS: 4

Page reference in F&M: 197;198

QUESTION 15

The operating system synchronises different processes with different resources, but a deadlock can occur. There are four necessary conditions for a deadlock to occur. Which of the following is the correct description of the ‘NO PREEMPTION’ condition?

1. The operating system cannot temporarily relocate a resource.
2. Only one process can hold a resource.
3. A process holds a resource even though it cannot use it until other resources are available.
4. All processes and resources involved form a loop.

ANS: 1

Page reference in F&M: 200

QUESTION 16

A list contains the following elements:

7 10 17 19 35 40 48 69 76 81 83 98 110

At the beginning, first = 1, mid = 7 and last = 13. What are the values of first, mid and last respectively after two more iterations of the binary search algorithm if the goal is 35?

1. 1, 3, 6
2. 1, 7, 13
3. 4, 5, 6
4. 7, 10, 13

ANS: 3

Page reference in F&M: 230; 231

QUESTION 17

A list contains the following elements:

30 34 44 21 63 15 89

What is the order of the elements in the list after three passes if selection sort is used?

1. 15 21 44 34 63 30 89
2. 15 30 21 34 44 63 89
3. 15 21 30 34 63 44 89
4. 15 21 30 34 44 63 89

ANS: 3

Page reference in F&M: 225; 226

QUESTION 18

Certain constructs are needed for a structured program. Which of the following is a construct that tests a condition?

1. Selection
2. Diversion
3. Sequence
4. Repetition

ANS: 1

Page reference in F&M: 217; 218

QUESTION 19

Which one of the following statements regarding search algorithms is true?

1. A sequential search is usually used for big lists.
2. A sequential search is generally very slow.
3. A binary search requires the list to be unsorted.
4. A binary search starts at the beginning of the list.

ANS: 2

Page reference in F&M: 230

QUESTION 20

An English-language-like representation of a step-by-step solution that expresses a logical solution to a particular problem of interest is best described as …

1. a process.
2. an algorithm.
3. a program code.
4. a pseudocode.

ANS: 4

Page reference in F&M: 219

QUESTION 21

Which one of the following is not true in relation to subalgorithms?

1. They are more difficult to understand than the main algorithm.
2. They are subunits of main algorithms.
3. They can be called many times by the main algorithm.
4. They can be broken down into other subalgorithms.

ANS: 1

Page reference in F&M: 218

QUESTION 22

The only language understood by computer hardware is … language.

1. scientific
2. natural
3. machine
4. mnemonic

ANS: 3

Page reference in F&M: 242

QUESTION 23

The two methods used in computer translation are …

1. decoding and interpretation.
2. interpretation and encoding.
3. compilation and encoding.
4. compilation and interpretation.

ANS: 4

Page reference in F&M: 245

QUESTION 24

The two methods that are used for translating a program into machine language both follow the same translation process. What is the first step in the process?

1. Syntax analysis
2. Semantic analysis
3. Code generation
4. Lexical analysis

ANS: 4

Page reference in F&M: 245

QUESTION 25

In which two forms can a final program in Java be?

1. An application or an applet
2. A function or a procedure
3. A procedure or an applet
4. An application or a function

ANS: 1

Page reference in F&M: 252

QUESTION 26

What name is given to procedures in the object-oriented paradigm?

1. Algorithms
2. Actors
3. Subroutines
4. Methods

ANS: 4

Page reference in F&M: 250; 251

QUESTION 27

Which programming language paradigm is based on deduction?

1. Functional
2. Procedural
3. Declarative
4. Object-oriented

ANS: 3

Page reference in F&M: 254

QUESTION 28

The waterfall model is one of the most common models for the development process of the software lifecycle. Which of the following would you consider to be the third stage of the model?

1. Design
2. Implementation
3. Analysis
4. Testing

ANS: 2

Page reference in F&M: 273

QUESTION 29

A number of diagrams can be used during the analysis phase of the object-oriented analysis process in software development. Which of the following will not be used during this phase?

1. State diagram
2. Class diagram
3. State chart
4. Use case diagram

ANS: 1

Page reference in F&M: 274; 275

QUESTION 30

What term refers to the process of breaking down a whole task into smaller tasks during the design phase of the software life cycle?

1. Modularity
2. Polymorphism
3. Subpackaging
4. Encapsulation

ANS: 1

Page reference in F&M: 277

QUESTION 31

Which one of the following statements regarding modules in a software system is not true?

1. Loosely coupled modules are more likely to be reused.
2. Cohesion between modules must be minimised.
3. Cohesion is a measure of how closely the modules are related.
4. Coupling is a measure of how tightly two modules are bound to each other.

ANS: 2

Page reference in F&M: 278

QUESTION 32

Maintainability is one of the measures for software quality. Maintainability includes …

1. reusability, interoperability and portability.
2. changeability, usability and correctability.
3. changeability, flexibility and testability.
4. reliability, timeliness and flexibility.

ANS: 3

Page reference in F&M: 279; 280

QUESTION 33

Documentation is needed for proper and efficient usage and maintenance of software. System documentation …

1. defines the software itself.
2. describes the installation and the servicing of the software.
3. can be a very powerful marketing tool.
4. shows how to use the software step by step.

ANS: 1

Page reference in F&M: 284

QUESTION 34

Which one of the given options is described by the following two statements?

 It represents a set of data items that share a specific relationship.
 It uses a collection of related variables that can be accessed either individually or as a whole.

1. Data structure
2. Method
3. Program
4. Object

ANS: 1

Page reference in F&M: 290

QUESTION 35

Which one of the following best describes what an array is?

1. A collection of fields that are all related to one object.
2. A sequenced collection of elements, normally of the same data type.
3. A collection of elements called fields.
4. A collection of elements called records.

ANS: 2

Page reference in F&M: 290

QUESTION 36

Which of the following operations cannot be defined on array data structures?

1. Deletion
2. Retrieval
3. Transversal
4. Append

ANS: 4

Page reference in F&M: 294

QUESTION 37

Given a node to insert into a linked list, if the predecessor node has a null pointer, then you are adding to …

1. the beginning of the list or an empty list.
2. the body of the list or the end of the list.
3. an empty list or the end of the list.
4. the beginning of the list or the end of the list.

ANS: 3

Page reference in F&M: 305

QUESTION 38

What is the first step in traversing a linked list?

1. Checking for the last node
2. Creating a walking pointer to the first node
3. Allocating a pointer to a node
4. Setting up a loop

ANS: 2

Page reference in F&M: 310

QUESTION 39

Which one of the following statements regarding linked lists is not true?

1. A linked list is a suitable structure if a large number of insertions and deletions are needed.
2. A linked list can grow infinitely and shrink to an empty list.
3. The name of a linked list is the name of the head pointer that points to the first node of the list.
4. A linked list is inefficient for storing data that needs a lot of insertions.

ANS: 4

Page reference in F&M: 310; 311

QUESTION 40

Which one of the following statements regarding sequential files is not true?
1. To access a file sequentially, a sequential file structure can be used.
2. There are only three files associated with an update program: the old and new master files, and the transaction file.
3. All the files need to be sorted on the same key to make the updating process efficient.
4. A loop is used to read and process records one by one.

ANS: 2

Page reference in F&M: 352

QUESTION 41

A hashed file is a random access file in which a … maps a key to an address.

1. function
2. transaction
3. relation
4. connection

ANS: 1

Page reference in F&M: 355

QUESTION 42

When a collision occurs, the address produced by a hashing algorithm is called the … address.

1. home
2. synonym
3. linked
4. prime

ANS: 1

Page reference in F&M: 358

QUESTION 43

Which one of the following collision resolution mechanisms uses a node that can accommodate more than one record?

1. Open addressing
2. Division remainder hashing
3. Bucket hashing
4. Linked list resolution

ANS: 3

Page reference in F&M: 359

QUESTION 44

Which one of the following statements regarding directories is not true?

1. A directory performs the same function as a folder in a filing cabinet.
2. In most operating systems a directory is represented as a special type of file that holds information about other files.
3. Directories are provided by most operating systems for organising files.
4. In most operating systems directories are organised like a tree abstract data type in which each directory has a parent directory.

ANS: 4

Page reference in F&M: 360

QUESTION 45

Which level of a database defines the logical view of the data?

1. Architectural
2. Internal
3. Conceptual
4. External

ANS: 3

Page reference in F&M: 372

QUESTION 46

Which one of the following is a database model that has become obsolete?

1. Object-oriented
2. Distributed
3. Relational
4. Network

ANS: 4

Page reference in F&M: 372

QUESTION 47

What name is given to a record of relation (table)?

1. Attribute
2. Tuple
3. Field
4. Cardinality

ANS: 2

Page reference in F&M: 375

QUESTION 48

Which query language is often used in relational databases?

1. ANSI
2. SQL
3. ISO
4. QRD

ANS: 2

Page reference in F&M: 375

QUESTION 49

In a fragmented distributed database, …

1. each site holds an exact replica of another site.
2. objects and their relations are defined.
3. data are localised.
4. any modification to data stored in one site is repeated exactly at every site.

ANS: 3

Page reference in F&M: 386

QUESTION 50

Which query language is often used in object-oriented databases?

1. HTML
2. Prolog
3. XML
4. Scheme

ANS: 3

Page reference in F&M: 386

II—oooOooo—II

Assignments help lecturers to see whether you understand the module, and they help you to learn the work and prepare for exams. They’re critical and compulsory – you won’t be allowed to write the examination unless you’ve completed the relevant assignments. Please note that you need to study hard in preparation for exams.

COS1521: Second Semester: ASSIGNMENT 01 – 2016

Due date: 24-Aug-16
Study material: (1) F&M: chapters 1–4; Appendices A & E (prescribed book)
(2) Tutorial Letter 102:
Part I: units 1–4
Part II: ALL (pages 24–74)
Part III: solution to self-assessment assignment

Do the relevant exercises in F&M, Tutorial Letter 102 and the self-assessment assignment before attempting this assignment. See more information about Tutorial Letter 102 in section 2.3 of this tutorial letter.

Submission procedure: Via myUnisa (see section 8.4)

Contribution to semester mark: 40%

Unique assignment number: 703201

This assignment is compulsory. To be admitted to the examination for this module, you must submit this assignment by 24 August 2016.

  •  Each multiple-choice question has four possible answers. Select the alternative you consider to be the most appropriate.
  • Submit your assignment via myUnisa by the due date. Do not be concerned if myUnisa is down on the due date. If this happens, we are notified about the situation and will take this type of delay into consideration. Try to resubmit the assignment as soon as myUnisa is up again.
  • The mark that you achieve out of a possible 40 marks will be converted to a percentage and will contribute 40% towards your semester mark.

Second semester: Assignment 01

QUESTION 1

According to the von Neumann model, which subsystem of a computer serves as a manager of other subsystems?

1. ALU
2. Input/output
3. Control unit
4. Memory

ANS: 3

Page reference in F&M: 5

QUESTION 2

We divide computer software and hardware into generations. In which generation are we currently?

1. Sixth
2. Third
3. Fifth
4. Fourth

ANS: 3

Page reference in F&M: 11

QUESTION 3

Which of the given options is not true? Since the 1950s, computers have generally become …

1. faster.
2. smaller.
3. cheaper.
4. heavier.

ANS: 4

Page reference in F&M: 10

QUESTION 4

Before cell phones (mobile phones) emerged, some people used to communicate using e-mail and others sent mail through the post office (snail mail). However, this communication gap has narrowed with the use of SMSs sent via cell phones. What name is given to the situation described here?

1. Dependency
2. Social justice
3. Digital divide
4. Privacy

ANS: 3

Page reference in F&M: 11

QUESTION 5

What name is given to a set of instructions that tells the computer what to do with data?

1. A program
2. An algorithm
3. A data processor
4. An operating system

ANS: 1

Page reference in F&M: 2

QUESTION 6

The first electronic special-purpose computer was called …

1. ABC
2. Pascaline
3. ENIAC
4. Pascal

ANS: 1

Page reference in F&M: 9

QUESTION 7

The area involving the design and writing of structured programs that follow strict rules and principles is known as …

1. software engineering.
2. application development.
3. algorithm design.
4. program development.

ANS: 1

Page reference in F&M: 8

QUESTION 8

Convert (10101)2 to a decimal number.

1. (5)10
2. (21)10
3. (17)10
4. (33)10

ANS: 2

Page reference in F&M: 26

QUESTION 9

Convert (B3.2)16 to an octal number.

1. (83.2)8
2. (263.2)8
3. (563.2)8
4. (263.1)8

ANS: 4

Page reference in F&M: 33

QUESTION 10

Which one of the following number representations is not correct?

1. (111.1)10
2. (12.01)2
3. (BAD)16
4. (417)8

ANS: 2

Page reference in F&M: 25

QUESTION 11

Convert (34)10 to a hexadecimal number.

1. (34)16
2. (22)16
3. (24)16
4. (42)16

ANS: 2

Page reference in F&M: 30

QUESTION 12

Convert (22)16 to a binary number.

1. (1111)2
2. (1010)2
3. (100010)2
4. (111100)2

ANS: 3

Page reference in F&M: 32

QUESTION 13

Which of the following is false?

1. (0)10 = (0)2
2. (10)8 is less than (10)10
3. (10)16 is an even number
4. (F)16 is equal to (14)10

ANS: 4

Page reference in F&M: 23-25

QUESTION 14

What is the 2’s complement representation of −14 using 5 bits?

1. (11110)2
2. (10100)2
3. (11001)2
4. (10010)2

ANS: 4

Page reference in F&M: 50-51

QUESTION 15

Which one of the following statements regarding sign-and-magnitude representation is not true?

1. There are two 0s in sign-and-magnitude representation: positive zero and negative zero.
2. Sign-and-magnitude representation is often used to quantise an analog signal.
3. Sign-and-magnitude numbers are subject to positive and negative overflow.
4. Sign-and-magnitude representation is commonly used to store integers.

ANS: 4

Page reference in F&M: 64

QUESTION 16

Samples are taken if all the values of an audio signal cannot be recorded. The number of samples needed to retrieve a replica of the original image depends on …

1. quantization.
2. encoding.
3. the bit depth.
4. the maximum number of changes in the analog signal.

ANS: 4

Page reference in F&M: 65

QUESTION 17

Which one of the following statements regarding the storing of audio or images is not true?

1. Vector graphics are suitable for storing the fine details of photographic images.
2. Audio storing can involve sampling, quantization and encoding.
3. In 2014, the dominant standard for storing audio was MP3.
4. Raster graphics are used when an analog image such as a photograph must be stored.

ANS: 1

Page reference in F&M: 67, 68

QUESTION 18

How many bytes should be used for a 32-bit pattern?

1. 4
2. 5
3. 16
4. 32

ANS: 1

Page reference in F&M: 43

QUESTION 19

If the input is 1010011, and the mask 0011111 is used to unset the input, what is the resulting output?

1. 0000000
2. 1111111
3. 0010011
4. 0000011

ANS: 3

Page reference in F&M: 81, 82

QUESTION 20

Calculate: (11011)2 + (1001)2.

1. (100100)2
2. (100010)2
3. (111000)2
4. (101100)2

ANS: 1

Page reference in F&M: 87

QUESTION 21

Calculate: (101011.1)2 + (11001.01)2.

1. (1110010.10)2
2. (1000010.01)2
3. (10010011.11)2
4. (1000100.11)2

ANS: 4

Page reference in F&M: 87

QUESTION 22

Calculate: (1010)2 XOR (1001)2.

1. (0011)2
2. (0110)2
3. (0111)2
4. (1111)2

ANS: 1

Page reference in F&M: 81

QUESTION 23

Use the arithmetic left shift operation on the bit pattern 11001101. The pattern is an integer in two’s complement format.

1. (10011010)2
2. (11001101)2
3. (11000110)2
4. (11100101)2

ANS: 1

Page reference in F&M: 85

QUESTION 24

Which logical operation on two input patterns has the following property?

“If a bit in one input is 0, there is no need to check the corresponding bit in the other input. The result is always 0.”

1. AND
2. OR
3. XOR
4. NOT

ANS: 1

Page reference in F&M: 79

Apply Boolean algebra rules to determine the simplest forms of the given Boolean functions in the following THREE questions.

QUESTION 25

What is the simplest form of the Boolean function (xx’ + y)’?

1. y’
2. 0
3. (x + x’)y’
4. 1

ANS: 1

QUESTION 26

What is the simplest form of the Boolean function x + xy’z’ + xy’z’?

1. y’z’
2. xy’z’
3. x
4. x + xy’z’

ANS: 3

QUESTION 27

What is the simplest form of the Boolean function (x’y)’ + y?

1. x + y
2. xy’ + y
3. 1
4. Y

ANS: 3

QUESTION 28

Consider the following Boolean function:
F(x,y,z) = m2 + m4 + m5 + m6

Which one of the following four Karnaugh diagrams represents the given function?

1.

2.

3.

4.

ANS: 1

QUESTION 29

Consider the following Karnaugh map:

Which one of the following four Karnaugh maps reflects the correct forming of groups?

1.

2.

3.

4.

ANS: 1

The next THREE questions refer to the Karnaugh map below.

QUESTION 30

Which term represents Group 1?

1. A’B’CD’
2. D’
3. A’
4. B’D’

ANS: 4

QUESTION 31

Which term represents Group 2?

1. DC’
2. C’
3. D’
4. CD’

ANS: 4

QUESTION 32

Which term represents Group 3?

1. ABD
2. AB
3. D
4. ACD

ANS: 1

The next FOUR questions refer to the following combinational logic circuit:

QUESTION 33

What is the output of Gate 1?

1. (x + y)’
2. x’y’
3. x’ + y’
4. (xy)’

Ans:2

QUESTION 34

What is the output of Gate 2?

1. [(x + y)’.z]’
2. (xy)’ + z’
3. (x’y’ + z)’
4. [(x’ + y’).z]’

Ans:3

QUESTION 35

What is the output of Gate 3?

1. [(x’ + y’).z]’ + z
2. [(xy)’ + z’].z
3. (x’y’ + z)’.z
4. [(x + y)’.z]’ +z

Ans:3

QUESTION 36

What is the output of Gate 4?

1. [(x’y’ + z)’.z]’.x’
2. [(x’y’ + z)’.z’x’]’
3. [[(x’ + y’).z]’ + z + x’]’
4. [(x + y)’.z]’ +z + x’

Ans:2

Consider the following scenario:

Three people are tree spotting in the bush. They spot the following trees:

Person A: willows & fever trees; Person B: willows & stinkwoods; Person C: milkberry trees & zebrawoods

When a person sees two kinds of tree (as mentioned above), the output is 1. For example, if A = 1, B = 1 and C = 0, Person A sees willows and fever trees, and Person B sees willows and stinkwoods, so the group of three people spot only 3 different kinds of tree.

A Boolean function F(A,B,C) outputs a 1 if a group of three people spot more than 3 different kinds of tree.

Different combination inputs for A, B and C are given in the tables in the following FOUR questions. Which alternative shows the correct outputs for F in EACH of the following FOUR questions?

QUESTION 37

Alternative 1 Alternative 2 Alternative 3 Alternative 4
A B C F F F F
0 0 0 0 1 0 1
0 0 1 0 1 1 0

Ans:1

QUESTION 38

Alternative 1 Alternative 2 Alternative 3 Alternative 4
A B C F F F F
0 1 0 0 1 0 1
0 1 1 0 1 1 0

Ans:3

QUESTION 39

Alternative 1 Alternative 2 Alternative 3 Alternative 4
A B C F F F F
1 0 0 0 1 0 1
1 0 1 0 1 1 0

Ans:3

QUESTION 40

Alternative 1 Alternative 2 Alternative 3 Alternative 4
A B C F F F F
1 1 0 0 1 0 1
1 1 1 0 1 1 0

Ans:3

II—oooOooo—II

Assignments help lecturers to see whether you understand the module, and they help you to learn the work and prepare for exams. They’re critical and compulsory – you won’t be allowed to write the examination unless you’ve completed the relevant assignments. All the best with Exams.

Understanding SharePoint 2016

I recently attended SharePoint Training Core Solutions of Microsoft SharePoint Server 2013. However, SharePoint 2016 is already out, meaning I need to get my hands on it!

SharePoint Server 2016 has been designed, developed, and tested with the Microsoft Software as a Service (SaaS) strategy at its core.

SharePoint is a robust and complex product. In my opinion, Microsoft has made it even more complex by having multiple products that use the SharePoint name. There have been various versions of SharePoint since SharePoint 2000, but in SharePoint 2016, we say goodbye to one of the SharePoint products and welcome some others. Let’s get the goodbye out of the way first. SharePoint Foundation included, for free, really were paying for as part of the licensing with Microsoft Windows Server was the most widely distributed version of SharePoint.

SharePoint Foundation has been discontinued with the 2016 SharePoint releases, so there is no SharePoint Foundation 2016. It’s easiest to think of the SharePoint Server products as a single, integrated platform that can be hosted in two different locations, and it has two broad levels of capabilities. SharePoint Server 2016 is the On premises version of SharePoint Server. It’s installed on your organization’s servers whether those are physical blades in a server room, or virtual servers like the one that I’m using for this course.

And there are two versions of SharePoint Server, Standard and Enterprise. SharePoint Server 2016 Standard includes the core capabilities of SharePoint, creating sites, having collaborative community, sharing content, content management, search, and so on. SharePoint Server 2016 Enterprise includes all of these and more, advanced search, business solutions, business intelligence, services that extend the capabilities of SharePoint. SharePoint Server Enterprise also costs more per user than SharePoint Server Standard, no surprise there.

SharePoint Online is the Microsoft hosted version of SharePoint. Organizations can purchase SharePoint Online with an Office 365 plan, or by itself. While the SharePoint Online and Office 365 plans aren’t called Standard and Enterprise, they actually are all some version of Enterprise. Nevertheless, the SharePoint Online package choices mirror the SharePoint On premises choices. The most expensive plans, the Enterprise plans, include the most features.

However, there are some amazing features like delve and video portals that are only available in SharePoint Online, they are not available on the On premises only version. So we have SharePoint Server 2016 Standard, SharePoint Server 2016 Enterprise, SharePoint Online in several different plans or flavors, and then one more item, SharePoint Designer. And there’s is no new 2016 version of SharePoint Designer, we’re using SharePoint Designer 2013, part of the Office family.

SharePoint Designer is installed on your local machine and it’s used to customize SharePoint, to create and customize sites, to work with forms, to build workflows, to brand SharePoint sites, and to create those composites that we saw in the earlier slide. The world is more complex than this simple table. A growing number of organizations are running SharePoint in a hybrid environment, which means they’re using both an On premises version of SharePoint Server, and SharePoint Online.

SharePoint 2016 was designed for this mixed environment and there’s increased support for hybridization being added on a regular basis. The new features that you’ll see in SharePoint 2016 On premises, Standard, and Enterprise, were developed and tested in SharePoint online across the last year or so. SharePoint Server 2016 really was born in the cloud. Microsoft is committed to future versions of SharePoint Server On premises, but SharePoint Online will continue to evolve with new features added on a regular basis, while SharePoint On premises will be modified as On premises software has been modified in the past, through patches and service packs.

So if you want to see the newest features of SharePoint, and what’s likely to be included in the next release of SharePoint Server On premises products, you would look at the Enterprise versions of SharePoint.

Assignment 02: Due date 05 September 2016 Compulsory

Module information

Software Project Management
Module code: INF3708
Bachelor degree Semester module NQF level: 7 Credits: 12
Module presented in English Pre-requisite: none Co-requisite: none
Purpose: To enable students to demonstrate their understanding of managing all phases of a software development project, which includes project initiation and process analysis, resource planning and allocation, project design, risk management, monitoring and control of a project, managing people and teams, implementation and coordination of projects.

Unique Number: 759379
Marks weight: 20%

ASSIGNMENT 02 – SEMESTER 2

ASSIGNMENT 02
Due date 05 September 2016
Study material Hughes & Cotterell: Chapters 2
Total marks 32 marks = 100%
If your assignment is late, please DO NOT PHONE OR E-MAIL asking for an extension but include a note in your assignment stating the reason for the late submission and we will decide whether or not it will be marked. This is a compulsory assignment

Instructions:

1. Complete this assignment and submit online in a .pdf format by performing the calculations.

2. The following unique number has to be assigned to the assignment:

Unique Number
759379

3. Show all your working (calculations).

4. This assignment consists of 5 questions.

QUESTIONS FOR ASSIGNMENT 02:

The cash flows of Projects 1 and 2 are given in the table below (in ZAR, South African rand, R):

Year Project 1 Project 2
0 -R155000 -R140000
1 -R5000 R15000
2 R40000 R5000
3 R50000 R20000
4 R50000 R30000
5 R50000 R60000
6 R30000 R70000

Table of cash flows for Project 1 and 2

Use this information to calculate the Net Profit, the Return on Investment (ROI), the payback period and the Net Present Value at 10% for each of these projects. Then answer Questions 1 – 5.

Solutions: coming soon:

1. Calculate the Net Profit for each project. (6 marks)

2. Calculate the Return on Investment for each project. (6 marks)

3. Calculate the Payback Period for each project. (6 marks)

4. Calculate the Net Present Value for each project. (12 marks)

5. Based on your calculation of the individual Return on Investment (ROI) of each project in question 2 above, which project would you select to develop? (2 marks)

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530 Login incorrect via ProftpD

How to fix “Error: Critical error: Could not connect to server” on ubuntu 14.04

Status: Resolving address of ftp.esgnet.lan
Status: Connecting to 10.11.1.21:21…
Status: Connection established, waiting for welcome message…
Status: Initializing TLS…
Status: Verifying certificate…
Status: TLS connection established.
Command: USER sibanda
Response: 331 Password required for esgnet
Command: PASS ***********
Response: 530 Login incorrect.
Error: Critical error: Could not connect to server

Solution:

Go edit /etc/shells

vi /etc/shells
# /etc/shells: valid login shells
/bin/sh
/bin/dash
/bin/bash
/bin/rbash
/usr/bin/tmux
/usr/bin/screen
“/bin/false”
/bin/false