USER MODELS AND MODELS OF HUMAN PERFORMANCE Essay

USER MODELS AND MODELS OF HUMAN PERFORMANCE - Essay Example One of the most thoroughly researched aspects of misconceptions is their resilience - they are hard to eliminate (Champagne, Klopfer, & Anderson, 1980; Larkin, 1983; as cited in Alexander, 1992). One cannot just make them go away by giving new information to students. Alexander (1992) attributes this to the complex networks of related information associated with misconceptions. This connection of misconceptions to information associated with a domain could cause students to alter other concepts too (Duschl & Hamilton, 1992). As students do not know that these misconceptions exist, they often work towards reinforcing them (Alexander, 1992). For example, while solving a problem, a student with misconceptions in algebra would try to create an alternative process that would conform to the misconceptions. In well-structured domains such as mathematics, computer programming, physics, and physical sciences, misconceptions have been researched consistently (Alexander, 1992). While misconceptions are not limited to some domains, not much research exists on why studies focused on well-structured domains or how the impact of misconceptions changes with domains. According to Alexander (1992), misconceptions have a "dispersive quality" - the more central a misconception is in a domain, the greater its impact on domain knowledge. According to Johnson (1986), programs written by novices with misconceptions reflect the misconceptions through characteristic bugs. Novices in C programming often use "=" for equality testing, rather than the required "= =" (Bull, S. et al., 2008). In C language, "=" is used to assign values and "= =" to compare for equality. Students who are new to C are likely to use "=" to compare values, as they learnt in mathematics and other programming languages. While the statement "If (x = y)†¦else†¦" is syntactically correct, the value of "y" is copied to "x". This happens

IP 2 - Art Essay Example | Topics and Well Written Essays - 500 words

IP 2 - Art - Essay Example The sphinx was smashed into fragments by Hatshepsut’s successor and cousin, but it was later reassembled the Metropolitan Museum of art in New York, where it is on view in gallery 131. The Statuette of Eros depicts a winged Eros, wearing Herakles’ lion skin. The sculpture’s dimensions are 39.4 cm x 26.7cm x 16.5 cm. The sculptor used terracotta (clay-based ceramic) to produce this masterpiece back in the 1st Century B.C. The statuette belongs to the Museum of Fine Arts, Boston. However, the Statuette of Eros is not on view. The sculpture is slightly in motion because Eros’s left hand is extended while his left hand is hidden behind his back. Ero’s posture shows that he is standing, but the arms show that there may be small movements. Ero’s wears a lion skin that covers him head to toe. There are traces of red on his chest, perhaps from the lion’s blood. Eros wear a circlet on his left thigh and a bracelet on his upper left arm. The sculpture captures the viewer because it portrays Eros as Herakles. The Statuette is chubby, beautiful (wings and ornaments), and seductive. Heracles of Mantinea or Heracles Combattant is a muscular representation of Heracles in action. The small structure is a representation of ancient Greek art and was sculpted between the 5th and 4th centuries B.C. The figure is made out of bronze and is 13 cm tall. The sculpture is located in the Room 22, Sully Wing of the Louvre Museum in Paris. However, the room is currently not open to the public. The small bronze represents a bearded man who appears to be taking a lunge with his left foot. Heracles’ right arm is raised behind his head (as if grabbing his mythical club), whereas his left arm is stretched forward (as if clasping something/someone). The aforementioned attributes, along with the powerful musculature, are a clear indication that the figure is a representation of the Greek legend

Securing MANET From Routing Attacks

Securing MANET From Routing Attacks CHAPTER 3 RESEARCH METHODOLOGY 3.1 RESEARCH PROBLEM The increasing demand and utilization of wireless technology is making the need for more secure wireless networks. From the security viewpoint MANET is one of the most interesting research fields. A MANET is generally exposed to vulnerabilities due to its open medium, rapidly varying network topology, lack of centralized control and lack of clear line protection and it suffers from a wide range of security threats and attacks. Attacks can be introduced into all the layers of protocol stack however the attacks on the routing layer are most detrimental. The attacks on the routing layer can be either from the outside the network or can take place within the network. The attacks from outside of the network contain no authentication information and can be avoided by employing authentication techniques and cryptographic schemes. The most common insider attacks include blackhole, wormhole, selective forwarding, RREQ and hello flooding, Sybil, sink hole and so on. Insider attackers are more critical compared to the outsider attack as the insider knows the valuable information and holds the access rights. To solve this issue, security solutions have to be proposed in order to secure MANET. The goal of this thesis is to analyse the impact of blackhole, wormhole and flooding attack under on-demand routing protocols such as AODV and DSR and to propose possible countermeasures to thwart these attacks. 3.2 AIM AND OBJECTIVES The aim of this research work is to secure the MANET from various routing attacks in order to improve the performance of the network. To achieve this aim, the following objectives are formulated: To analyse the impact of blackhole, wormhole and flooding attack under AODV and DSR routing protocol To analyse packet delivery ratio and end-to-end delay in case of black hole, wormhole and flooding attack using AODV and DSR protocol and the results of AODV and DSR are compared to evaluate which of these protocols are more susceptible to these kind of attacks. To develop defence mechanisms against blackhole, worm hole and flooding attack under AODV and DSR protocol. 3.3 SCOPE OF THE THESIS There exists various routing attacks in MANET such as blackhole, wormhole, Sybil, selective forwarding and flooding attack and so on. This research work considers only blackhole, wormhole and flooding attack and its impact on on-demand routing protocols such as AODV and DSR is analysed. Efficient detection techniques have been developed to mitigate the effect of these attacks against AODV and DSR routing protocol. The performance of these routing protocols using the detection techniques are evaluated in terms of packet delivery ratio and end-to-end delay. 3.4 SYSTEM ARCHITECTURE This research focuses on blackhole, wormhole and flooding attacks on AODV and DSR protocol. The architecture of the proposed system is given in Figure 3.1. Efficient techniques such as MSBD and ABM, MCHOP and CDCF, MCLUT and TSPS has been developed to detect blackhole, wormhole and flooding attacks under AODV protocol and techniques such as ABM, CDCF and TSPS have been developed to mitigate against blackhole, wormhole and flooding attacks under DSR protocol. The proposed techniques detect these attacks effectively and provide a secure path. Figure 3.1 An Overview Of Attacks On MANET Routing Protocol And Their Detection Techniques 3.5 DETECTION TECHNIQUES AGAINST BLACKHOLE, WORMHOLE AND FLOODING ATTACKS 3.5.1 MultiShared Bandwidth Approach for Blackhole Attack Detection The AODV protocol is vulnerable to the well-known black hole attack. In this thesis, the multishared approach is designed to prevent any alterations in the default operation of either the intermediate nodes or the destination nodes. Here, watchdog mechanism is incorporated with MultiShared Bandwidth (MSBD) approach to detect misbehaviour or abnormal activity of a node, once an abnormal activity is observed MSBD is initiated. The MSBD converts the data into 16 bit and further splits the 16 bit data into multiple shares. When multishared data is received by a node it checks the bandwidth of neighbouring nodes to transmit the data. Then it chooses the nodes with highest bandwidth along the path and sends the data through these selected paths. 3.5.2 MCHOP-A Cluster based Approach for Wormhole Attack Detection In AODV routing protocol, the intruder will attack the network using the attack like wormhole during the route discovery stage. A cluster based algorithm has been proposed to detect a wormhole attack on AODV routing protocol. In this approach, the network is partitioned into several clusters based on density based clustering algorithm. Here, AODV protocol is modified in such manner that it detects the wormhole attack based on the hop count comparison and time taken to receive RREP packets. The cluster head is responsible for adding certain fields such as hop count, destination address to the RREQ packet and it broadcasts it to the other cluster head in the network. Whenever the intermediate node receives the RREQ packets, it sends an ACK to the source node with hop count information and broadcasts it to the destination node. The destination node then unicasts the RREP to the source node utilizing the reverse path. The RREP is then validated by source node using the hop count informat ion and time taken for receiving the packet. 3.5.3 MCLUT- Clustering Approach for Flooding Attack Detection The proposed MCLUT approach is used to detect the flooding attack node by enabling the clustering approach and calculating the threshold value of each node in the cluster. Here dynamic threshold value is used. The threshold value is estimated based on the queue length of a node and its neighbour in the cluster. If a node does not satisfy the threshold value then it is considered as an intruder. Once the cluster head confirms that the node is intruder it then broadcast the message to other nodes to isolate the node from the cluster and the suspicious node is kept in observation. 3.5.4 Anomaly based Behaviour Monitoring Algorithm for Black hole Attack Detection under AODV and DSR protocol The proposed Anomaly based Behaviour Monitoring (ABM) algorithm detects blackhole attack on AODV and DSR protocol. This technique periodically checks and verifies whether the number of packets disseminated between source and destination are equal. Through this comparison, the source node could detect the presence of black hole node. 3.5.5 Channel Detection and Cut Defalconin algorithm for Wormhole Attack Detection on AODV and DSR Channel Detection and Cut Defalconin (CDCF) algorithm is proposed to detect wormhole attack on DSR and AODV protocol. This method detects a wormhole attack in the network based on the threshold limit and then provides a new route to forward the packet from source to destination. The threshold value is determined based on Round Trip Time (RTT) and a delay per hop (DPH) is calculated based on the RTT, while forwarding packet from source to destination with the malicious nodes, its take less Round Trip Time (RTT) to forward the packets to the destination, when forwarding packet from source to the destination without any malicious node attack, it takes more RRT to forward the packets to the destination. If the DPH of a node is smaller than all other nodes, then it indicates the wormhole attack presence. 3.5.6Transmission Sequence Based Packet Scanner Algorithm for Flooding Attack Detection on DSR and AODV. Flooding is a Denial of Service (Dos) that is designed to bring down the service of the network by flooding it with huge volume of traffic. Transmission Sequence based Packet Scanner (TSPS) technique has been proposed to detect flooding attack on DSR and AODV. The TSPS identifies the presence of flooding attack based on source id, empty packet, number of hops and transmission sequence number.

Oakland, CA :: essays research papers

The Forgotten City This paper will discuss the many unique aspects of Oakland, California. Divided into five major parts, Oakland is a very diverse city. The five major parts include: Downtown Oakland which is located in the heart of the city, East Oakland which consists of the majority of the city, West Oakland, North Oakland, and the Oakland hills where the terrain is quite different from other parts of the city. While many may perceive the population to mainly consist of African Americans and Whites, there is a significant growing population of Latinos, and Asians. The topics covered in this paper will shed light on the city of Oakland itself, and discuss the unique city that it is. I will also give my personal experience and perception on the city, after living there for 16 years of my life. History In historical terms the city of Oakland was named after the many Oak trees that inhabited the land when the city was established. Oakland was first founded in 1852 and is located on the East side of the Bay Area in Northern California.(Oakland History) Native Americans had previously lived in the area for over 5 thousand years before many arrived for the Gold Rush, and put down their roots. The famous author Jack London also spent many of his earlier years in Oakland, and his works have said to have been influenced by the city. My personal perception of Oakland is that it has always been the forgotten city in the Bay Area. Almost no one would notice that famous actors Clint Eastwood, and Tom Hanks spent many of their childhood days in the city. Basketball future hall of famers Gary Payton and Jason Kidd also spent their childhood days there. Baseball hall of famers Reggie Jackson and Ricky Henderson still own homes in the city. In modern times Oakland is known as the main metropolitan city in the East Bay. The city possesses 3 professional sports teams, which have a population of just below 400,000. Oakland is also the 3rd largest metropolitan city in the Bay Area behind San Jose, and San Francisco.( Encyclopedia Britannica ) The city mayor is the ex Governor of California Jerry Brown. Located in Alameda County Oakland’s area consists of a total square mileage of 78.2 miles, of which 56.1 miles is land, and the latter consisting of water.( Encyclopedia Britannica ) Oakland also possesses the 3rd largest seaport on the west coast.

Women(KAFA)

In the Ad they are showing the effects of verbal abuse on women. They are trying to do something about it and raise awareness to all form of abuse, which is not always physical. They are showing a place where women can go to, someone who would help and do something about it. Most of the women don't talk about being abused because they are afraid of the disgrace. The women are being abused because of the Idea that men have that once they are married to them they became their property; they get to do whatever they want to do to them.KAFA are trying to enlighten the people and let them getting a little bit wiser about women's rights and they are now going to help abused women. All what women have to do Is to call them and tell what she is suffering from. The tone they are using here serious, because this situation is becoming all over the place and no one seems to bat an eye about, shocking; because this abuse will live for many years with the woman and hunt her down and spoils every mo ment of happiness that she ever dreamt of having and that could to lead hem to commit suicide.With KAFA they don't have to suffer in silence they will give them help. KAFA Is looking for a better society where all Its citizens live free of violence and where they have equality. In general KAFA started to make these Ads to spot the light on certain behaviors in our culture. They are trying to get us on track to recognize women's rights. One factor Is that women are considered some kind of slave for the men desires. Another factor is that the women role is shortened as an indoor role only. However, woman is an ffective fgure in society she could do any thing as better as men.The biggest factor that led to this campaign Is the Arab Spring; after what happened In the region has opened the eyes wide open to see that we are In the phase of changing. Therefore; women became part of the Arab Spring and now they have central role in that transition. In KSA women now have the right tovote In Saudi parliament that only means one thing, which is we are at the doorstep of new era of a democratic world. All of these factors helped to create this organization to increase awareness of Women's rights.The main thing KAFA Is trying to advocacy and builds awareness of women's status and issues in our region, for a better tomorrow with equality. This organization is all about having a better society with no violence and women slavery. This civil society organization Is looking to mitigate the causes and results of violence and exploitation of women through advocacy and lobbying. The message for women in this Ad is you dont have to suffer from verbal abuse or any other kind; we are here to get you out of the gutter.Dont stay In the shade come to the bright side. I nls AO was a consequence 0T wnat Is nappenlng lately In tne region, wnlcn Is tne Arab Spring. All of the Arab countries that suffered from dictatorship are now up against their regimes. It is started from Tunisia all the way to Yemen. The people are claiming their rights, democracy and fair elections etc. Several countries from the region are undergoing fundamental transitions, including holding elections, making new Constitutions, new laws and establishing mechanisms for transitional Justice.The outcome and the results of these processes are critical and very sensitive for the rights of women and their status in the new era of democracy. The Arab uprising has empowering women to claim a wider and larger presence and role in the public, and that is a revolutionary thing, and that is a good thing to exclude the decades of gender stereotyping. The position of the women has been difficult. In 2002 the first Arab Human Development Report cited the lack of women's rights is caused of, lack of political freedoms and poor education, that hampered the region's progress.Nowadays, Women and men are seeking human rights, Justice and equality after decades of dictatorship. That thing yielded of making companies who afraid of excluding women from the revolution because the revolution impact on women still unclear. Most of the people in the revolution are hoping this revolution will boosts women's rights, but the outcome still didn't match up their expectations. Some Islamic-extremes parties that have been raised to the authorities are considered as a threat to women's rights. In these rough days women is playing a very important role n the revolution.In Libya women smuggled medicine, weapon all of that Just to help the rebels and prove that they are helpful and could be an important part in their revolution. Even now while the situation still raging some people start a revolution inside of revolution all that Just to keep women's rights within the aims of the main revolution. KAFA made these Ads to spot the light on women abusing. It is not same any more the abusing is not physical it took another shapes nowadays; it became verbal, insulting women with hurtful words.Therefore; they are try ing show what they are fighting for and it's a thing people should be up against the same as the dictatorship regime. A lot of doubt that the women case will remain the same as it was before because men are looking for their own sake. Consequently; organizations all around the region including KAFA are making people aware to not forget women in our revolution and that we are standing for the same case and it is a chance to write a new chapter in our history of freedom and equality with no sexism and gender stereotyping. Eventually stop women abusing.

7 Days of Prayers for the Souls in Purgatory Essay

PREPARATORY PRAYER My Jesus, by the sorrows You suffered in Your agony in the Garden, in Your scourging and crowning with thorns, in Your journey to Calvary, in Your crucifixion and death, have mercy on the souls in purgatory, and especially on those that are most forsaken; deliver them from the torments they endure; call them and admit them to Your most sweet embrace in paradise, where You live with the Father and the Holy Spirit, one God, for ever and ever. Amen See more: Homeless satire essay Prayers from The Raccolta (Here say the prayer for the day) 0ur Father Our Father in Heaven, Your Kingdom come; Your will be done on earth, as it is in Heaven. Give us this day our daily bread; and forgive us our sins, as we forgive those who sin against us; and lead us not into temptation, but deliver us from evil. Amen. Hail Mary Hail Mary, full of grace, the Lord is with you; blessed are you among women; and blessed is the fruit of your womb, Jesus. Holy Mary, Mother of God, pray for us, sinners, now and at the hour of our death. Amen. Eternal Rest Eternal rest, grant unto them, O Lord; and let perpetual light shine upon them. May they rest in peace. Amen. Concluding Prayer Merciful Father, hear our prayers and console us. As we renew our faith in Your Son, whom You raised from the dead, strengthen our hope that all our departed brothers and sisters will share in His resurrection, who lives and reigns with You and the Holy Spirit, one God, for ever and ever. Amen. SUNDAY O Lord God omnipotent, I beseech You by the Precious Blood, which Your divine Son Jesus shed in the Garden, deliver the souls in purgatory, and especially that one which is the most forsaken of all, and bring it into Your glory, where it may praise and bless You forever. Amen. Our Father, Hail Mary, Eternal rest, etc. MONDAY O Lord God omnipotent, I beseech You by the Precious Blood, which Your divine Son Jesus shed in His cruel scourging, deliver the souls in purgatory, and among them all, especially that soul which is nearest to its entrance into Your glory, that it may soon begin to praise You and bless You forever. Amen. Our Father, Hail Mary, Eternal rest, etc. TUESDAY O Lord God omnipotent, I beseech You by the Precious Blood of Your divine Son Jesus that was shed in His bitter crowning with thorns, deliver the souls in purgatory, and among them all, particularly that soul which is in the greatest need of our prayers, in order that it may not long be delayed in praising You in Your glory and blessing You forever. Amen. Our Father, Hail Mary, Eternal rest, etc. WEDNESDAY O Lord God omnipotent, I beseech You by the Precious Blood of Your divine Son Jesus that was shed in the streets of Jerusalem while He carried on His sacred shoulders the heavy burden of the Cross, deliver the souls in purgatory and especially that one which is richest in merits in Your sight, so that, having soon attained the high place in glory to which it is destined, it may praise You triumphantly and bless You forever. Amen. Our Father, Hail Mary, Eternal rest, etc. THURSDAY O Lord God omnipotent, I beseech You by the Precious Body and Blood of Your divine Son Jesus, which He Himself on the night before His Passion gave as meat and drink to His beloved Apostles and bequeathed to His Holy Church to be the perpetual Sacrifice and life-giving nourishment of His faithful people, deliver the souls in purgatory, but most of all, that soul which was most devoted to this Mystery of infinite love, in order that it may praise You therefore, together with Your divine Son and the Holy Spirit in Your glory forever. Amen. Our Father, Hail Mary, Eternal rest, etc. FRIDAY O Lord God omnipotent, I beseech You by the Precious Blood which Jesus Your divine Son did shed this day upon the tree of the Cross, especially from His sacred Hands and Feet, deliver the souls in purgatory, and particularly that soul for whom I am most bound to pray, in order that I may not be the cause which hinders You from admitting it quickly to the possession of Your glory where it may praise You and bless You for evermore. Amen. Our Father, Hail Mary, Eternal rest, etc. SATURDAY O Lord God omnipotent, I beseech You by the Precious Blood which gushed forth from the sacred Side of Your divine Son Jesus in the presence and to the great sorrow of His most holy Mother, deliver the souls in purgatory and among them all especially that soul which has been most devout to this noble Lady, that it may come quickly into Your glory, there to praise You in her, and her in You through all the ages. Amen. Our Father, Hail Mary, Eternal rest, etc.