A review on delay-minimized routing protocol in mobile cognitive ad hoc networks

A review on delay-minimized routing protocol in mobile cognitive ad hoc networks Mobile Cognitive Ad Hoc Networks is one of the cognitive radio networks which is the advanced networking technologies for spectrum scarcity problem constrain in the Federal Communication Commission (FCC). The cognitive radio networks are the cognitive network which abjects its network parameters with respect to the network environment. In cognitive radio network two users namely the primary and secondary or cognitive users will access the available spectrum to communicate each other when the spectrum is accessed by the primary user the secondary user must leave the spectrum and access the spectrum when spectrum holes available for transmission. So routing is challenging issues in cognitive networks and it is very challenging in mobile cognitive networks due to the node mobility, primary user interface and spectrum scarcity in this paper some routing protocols based on mobile ad hoc cognitive networks and a review on the delay-Minimized routing protocol are presented. Cognitive Radio Networks (CRN) is the new technology used to overcome the spectrum scarcity problem in current wireless networks by the Federal Communication Commission (FCC). In cognitive radio network is a network which has primary and secondary users which access the network based on Dynamic Spectrum Access (DSA). The primary user is the licensed user and secondary user is unlicensed user when the licensed user is accessing the spectrum the unlicensed user are not allowed so the secondary user has to sense the spectrum periodically to find the presence of primary user, presence of primary user is in dynamic in nature so the spectrum holes created by primary user is dynamic so the Cognitive user uses the DSA. While using the DSA routing is the challenging in cognitive radio networks. Classification of Cognitive radio networks Cognitive Radio Networks (CRN) is of infrastructure and infrastructure less, in infrastructure network it has a fixed structure like base station primary users secondary users and so on, in infrastructure network it has no fixed structure. Centralized and Decentralized networks the Centralized network is the network in which has on the base station in the central and have primary users are present. The decentralized network is the network which has no centralized base station and has the secondary users to communicate and primary users Static and dynamic networks the static networks the position of the base station, primary users and secondary users are fixed but in the dynamic (Ad-Hoc) the position on primary users and the secondary user will change (Mobility is nature). Routing in Cognitive radio networks Routing in Cognitive radio networks is based on available spectrum and knowledge of spectrum to nodes in the network. Routing solutions for the Cognitive radio networks are of two types one is Full Spectrum Knowledge routing and second is Local Spectrum Knowledge routing. Local Spectrum Knowledge routing has Minimum Power Routing, Minimum Delay-based Routing, Maximum Throughput-based Routing, Geographic Routing and Class-based Routing. Spectrum-Aware Routing (SPEAR) Spectrum-Aware Routing (SPEAR) is an on-demand and link-based protocol support end-to-end throughput by integration of flow-based and link-based approaches, it used RREQ for route discovery by control channels it takes decisions with the collaboration of PHY and MAC layers it handles mobility issues with Timeout field in periodic channel reservations messages. It takes the best path by maximum throughput, minimum hop count and link quality it has a communication overhead by route setup and route tear down. Spectrum-Aware Mesh Routing (SAMER) Spectrum-Aware Mesh Routing (SAMER) is a link state routing protocol with a minimum hop count and spectrum availability it gives end-to-end thought with the path with high spectrum availability, long-term stability and short-term opportunistic utilization of spectrum. The routing decisions are taken by PHY and MAC layers. Spectrum-Aware On-Demand Routing Protocol (SORP) Spectrum-Aware On-Demand Routing Protocol (SORP) is an AODV protocol with control channel which uses the path delay and node delay (switching and back off delay) for path selection. In route discovery phase RREQ message is broadcast with an SOP append in the packet the control channel exchange the routing protocol messages and it gives end-to-end thought put SORP doesn’t have link failure handling mechanism. Multi-hop Signal-transceiver Cognitive Radio Network Routing Protocol (MSCRP) Multi-hop Signal-transceiver Cognitive Radio Network Routing Protocol (MSCRP) is an AODV protocol with on control channel. It is a spectrum aware routing and leaves/ joins messages of the nodes so it has the communication overhead of RREQ. In the route discovery phase, all nodes append their sate information and available channels set. The routing decision is taken with the collaboration of MA C, Physical and Network Layers. Routing in Opportunistic Cognitive Radio Networks Routing in Opportunistic Cognitive Radio Networks is an on-demand graph-structured network protocol which uses the routing metric based on the probabilistic definition of available capacity over channel it has no link failure handling capacity and it discovers the route by using OSPF, Dijkstra-link algorithm. By using this Dijkstra-link algorithm it gives end-to-end throughput Local Coordination Based Routing and Spectrum assignment in Multi-hop Cognitive Radio Networks Local Coordination Based Routing and Spectrum assignment in Multi-hop Cognitive Radio Networks is a modified version of AODV which is on-demand routing protocol it has full mesh topology which uses channel scanning and beacon broadcast for neighbor discovery with control channel used for load balancing in routing. The route discovery is done by using RREQ and route decision is based on MAC and Network Layer. It has a link failure handling capability which gives less end-to-end delay and performance. Multipath Routing and Spectrum Access (MRSA) Multipath Routing and Spectrum Access (MRSA) is Mesh routing protocol based on round robin fashion data striping with minimum hop count by route discovery with control channel, Broadcasting RREQ messages. The messages sent to nodes periodically it can handle path failures by sending RERR messages and it has a communication overhead based on multiple flows on a single radio. Cognitive Tree-based Routing (CTBR) Cognitive Tree-based Routing (CTBR) is the tree-based routing protocol with centralized routing it broadcast the root announcement (RANN) message periodically with a packet and used cumulative metric for path selection. It selects the path based on local and global decision schemes. It does not have a route recovery mechanism to handle link failure s and it has a control bytes transmission overhead. Fault-Tolerant Cognitive Ad-Hoc Routing Protocol (FTCARP) It is a fast and efficient routing protocol for route recovery in presence of path failures during data delivery. It uses different route recovery mechanisms for different path failures. Cognitive Destination Sequence Distance Vector (C-DSDV) Protocol It is a table-driven routing protocol. To optimize the system performance of multi-hop CR ad-hoc networks by using multichannel routing table are updated immediately when there is a change in channels the techniques is that combines the routing and channel allocation. In route discover phase common control channel use to broadcast the route updating in the routing table in this protocol best path selection is based on sequence number. In C-DSDV channel switching is used to improve the system performances. If there are more primary users routing overhead will be increased Cognitive Ad-Hoc On-demand Distance Vector (C-AODV) Protocol Cognitive Ad-Hoc On-demand Distance Vector (C-AODV) Protocol is based on AODV a wireless network protocol it is designed according to avoid primary users activates regains for routing formation and packet discovery. It gives the minimized route cost by forwarding packets through the joint pat h and channel selection at each node it takes the advantage of the availability of multiple channels to improve the overall performances. SER-Spectrum and Energy Aware Routing Protocol SER is an on-demand routing protocol which provides high throughput in multi-hop networks it selects an energy efficient route and assigns channels and timeslots for a connection request. The communication segment assignment algorithm is used for balances traffic load among the CR users. In route discovery phase it broadcasts Route Request Messages to other nodes so it has routing overhead of RRE, RREP, RERR and ROP messages. GYMKHANA Protocol GYMKHANA is an on-demand routing protocol and an enhanced version of AODV used the GYMKHANA algorithm using virtual graphs and evaluate the cost by using the Laplacian matrix. It has a secondary user’s self-interference overhead. UNITED NODE Protocol UNITED NODE Protocol is a distributed and efficient based interference-aware routing protocol. It incorporates the spectrum availability cost and interference metrics into the routing algorithm to find better routes between the nodes it repairs routes by using route preservation method. It provides adaptability to the environment and increases throughput and reduces data delivery latency. DELAY-MINIMIZED ROUTING PROTOCOLS FOR MOBILE COGNITIVE RADIO Ad-Hoc NETWORKS POPCORN Protocol ROPCORN Protocol is the on-demand routing protocol which was designed for data transportation using link modeling and used to minimized delay for a set of users in the network. It broadcast the packets in link with the low cost and no primary user is affected. POPCORN is based on RACON protocol it uses buffers in the intermediate nodes and forwards the packets there is no overhead due to the use of spectrum availability and load estimation, the optimal route selection is based on the spatial or temporal locality of link disconnection. SEARCH A Routing Protocol It is the on-demand routing protocol and an enhanced version of AODV which is based on the geographic routing and follows the greedy forwarding and PU avoidance for joint channel-path optimization algorithm to find the best path. SEARCH undertakes both the path and selection to avoid PU activity region and tries to maintain end-to-end latency it has routing overhead due to the RRE, RREP, RERR and ROP messages. Link Prediction-Based Ad aptive Routing Link Prediction-Based Adaptive Routing is based on the link-availability prediction. The link –availability prediction considers primary user activity and user mobility. This routing reduces the energy consumption and gives the least delay by enhances network performance. It works based on link prediction and topology control Joint Routing and Channel Assignment Joint Routing and Channel Assignment (JRCA) approach based on delay prediction and a heuristic algorithm which used the collision probability and Link Stability Prediction. It is an on-demand routing protocol which user AODV type of routing with heuristic values and can find out the path with minimal end-to-end (e2e) delay. Adaptive Delay Tolerant Routing Protocol (ADTRP) The ADTRP algorithm finds a stable sequence of instances of the mobile graph and the communication topology of interest such that the number of transitions from one instance of the topology to another in the sequence is the global minimum. The algorithm uses the average lifetime of the mobile graphs in the stable sequence for communication topology and it is a generic for a stable sequence of any communication topology it uses the heuristic topology for routing so it improved throughput, better packet delivery ratio, decreased packet drop and reduced delay. STOD-RP: A Spectrum-Tree Based On-Demand Routing Protocol STOD-RP is an on-demand routing protocol which was designed for reduces the control overhead and average end-t-end delay minimization and it is an extension of the original Ad-hoc On-demand Distance Vector (AODV) protocol which uses spectrum tree addresses, spectrum decision and route selection in an efficient way for this route matrix is used. Fast and efficient spectrum-adaptive route recovery method is used when the path is damaged. In routing is challenging issues in cognitive networks and it is very challenging in mobile cognitive networks due to the node mobility primary user interface and spectrum scarcity this paper concludes that every protocol is designed for overcome certain problem in networks one is for multiple problems and one is for single problem like improving performance, minimized end-to-end delay, overall throughput increasing and so on. There is a for more protocols or improved versions of protocols for increasing problems and recruitments. In further work on this paper, a delay minimized routing protocol is proposed and implemented that improved version protocol in NS3 will be presented

Tsunami Disasters Essay Example | Topics and Well Written Essays - 750 words

Tsunami Disasters - Essay Example In particular, the port of Chennai on the east coast of India sustained moderate damage. The local fishing fleet was affected, with a number of boats overturned or washed ashore within the harbor. Overall economic losses from the 2004 Indian Ocean Earthquake and Tsunami disaster are estimated at$10 billion, with 75% of the loss attributed to the damage inflicted by Indonesia, Thailand, Sri Lanka, and India. The Southwestern costal area of the island Hokkaido was affected by the earthquake. The most affected area was in east of island Okushiri and was 100 by 125 kms. Waves soared high. They were from 5 to 12 m high and inundated the area around the island. The highest wave run-up along the southwest coast and was about 30.5 m on a limited area. Most of the deaths were on Okushiri island. The number of missing was expected to be higher because it is a tourist area. Â  540 houses were destroyed by tsunami and fire caused by earth quake, 154 houses and other properties were heavily damaged and 1,826 were slightly damaged. 31 public buildings were damaged and some were severely destroyed. Highways were destroyed in at least 365 locations and Railway lines were completely damaged at 124 locations. Port facilities and all other infrastructure in direct path of tsunami were extensively damaged, including power, water, telecommunications, transportation, and sewage. Tsunami didn’t damag e the sewage treatment plant at Apnea. Naturally high sand dunes protected it The powerful Earthquake of Hokkaido occurred in south west, the Sea of Japan. The earthquake’s epicenter was at a depth of 34 km on the Sea floor and was very close to the Okushiri Island. The island was hit by tsunami in less than 4 minutes after the earthquake and that left no time for the people of the island to evacuate. Many homes were constructed along the sea side which explained the high toll of victims. Despite only

Country Risk Ananlysis Research Paper Example | Topics and Well Written Essays - 2250 words

Country Risk Ananlysis - Research Paper Example Some risks can be diversified away through investing in portfolios of investments which diversify each other’s risk. The risk that can be diversified away is called diversifiable risk or unsystematic risk. On the other hand systematic risk cannot be diversified and is thus also called un-diversifiable risk. Economic and political risk is inherent risks of operating in a country. The economic risk is the risk that economy of that country would change for the worse. This change could be due to bad management or uncomprehend able natural causes, such as reduction in oil prices for a country which has oil as its primary export. Political risk on the other hand points towards the stability in the country. This is the risk that there would be political turmoil in a country which would result in loses on investment. The recent changes in the Arabian Peninsula are changing the shape of Arab politics for ever. There have been major political changes in countries like Egypt, Libya and S yria. These political changes would in due course of time bring positive changes in the region and contribute to the economic stability and wellbeing of local. However these changes have also created a sense and environment of uncertainty in the political environment of the region. There is confusion as to which country would be affected by this political upheaval next. Amongst this political turmoil lies a country of 1.7 million people known as Qatar. The State of Qatar is located in the Middle East and shares its borders with the Gulf and Saudi Arabia. The country is a monarchy controlled by the Al Thani family. Other monarchies in the region are threatened by political upheavals; Qatar is no different due to its political system. However Qatar is still a peaceful country and there have been no apparent signs of any political upheavals. One of the reasons is the sound economic situations of the country. The economy of Qatar is growing rapidly and is considered one of the fasted gr owing economies of the world. The nation has a per capita annual GDP of 97,000 dollars, which is one of the highest in the entire world. The nation is rich with oil and gas reserves. However instead of simply consuming these resources like many other Arab nations, Qatar has strived to build itself as a strong economic power through development of infrastructure and industry. The economic growth is stable due to a strong inflow of foreign capital due to oil exports. This stability plays a primary role in reducing the financial risk of the country. The purchasing power parity of Qatar according to CIA Fact-book is estimated to be $123 billion. This is an increase of approximately 20% from previous years. Due to a rick economy the locals are not an active part of the country’s workforce. However efforts are being made to bring about a change in this department. The main hindrance in these efforts is the availability of an excellent social welfare system, which allows people to l eave lives near 0 % present of poverty. This can be seen by the high per Capita GDP of Qatar which makes it one of the richest nations in the world. The country risk of Qatar has been defined as CRT-3. Risk tier 3 is defined as Developing legal environment, legal system and business environment with developing capital markets; developing insurance regulatory structure. This means that the country has very low economic risk. This low risk is due to the rapid growth of GDP

Hoop Dreams :: Hoop Dreams

Hoop Dreams  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚      Hoop Dreams is a story about two young men who want to become basketball players in the NBA. The author Ben Joravsky wrote the book. The idea for the book came from the documentary movie, Hoop Dreams, which is a true story. Arthur Agee and William Gates are the names of the two boys who were followed from eighth grade to twelve grade to do the movie. Arthur Agee was a 5'6 125 pound guard from the playgrounds of Chicago when St Joseph recruiters saw him. Arthur was playing against guy's three years older than he was and he was still the best in the neighborhood. Arthur's parents Bo and Sheila Agee were very poor people who were on cocaine and could not support their family. Big Earl, the guy who recruited Arthur told his family that St. Joe's would be able to pay Arthur's tuition if he played basketball for them. Arthur went to St. Joe's and met William Gates. They had become friends in grade school but had never really done anything together. Eventually William turned out to be the b etter player and all the attention and money was focused on him. Therefore, Arthur was booted out of St. Joe's in the middle of the school year. He was forced to enroll at Marshall, the area public school. As a result, Arthur could see his dreams of the NBA were slipping away. Along with that, he couldn't keep his grades up enough to attend a Division I school. He and the Marshall Commandos ended up going downstate Arthur's senior year. They finished third in the state overall. Arthur ended up going to a junior college named Mineral Area in Flat River Mississippi. After his two years in Mississippi, Arthur received a scholarship to Arkansas State. He finished his degree in communications and he graduated. Arthur never did reach his dream of going to the NBA, at least yet. As you can see, it takes a lot for an inner city boy to try and reach his dream, but most of the time it never happens. William Gates was also 14 when he was recruited to go to St. Joseph. He and Arthur both had to wake up around 5:30 every morning so they could get on the subway to make it to school in time.

Crash, Boom, Bang

Crash, Boom, Bang Janie Bunce Abstract The movie â€Å"Crash† was voted the best movie of 2005 for good reason, it deals with subjects that others were probably afraid to tackle. As the name implies it starts with a car crash, but in doing so reveals only one of the metaphors used in the movie. Other metaphors used in the movie allow us to view the culture shock that many people see on a daily basis, especially when dealing with different ethnicities, religions and races.Los Angeles is shown in its true colors where people live in a fast paced city where more than the cars move at a faster pace. These characters speed through their lives without notice of other people around them. It is as if some of them have blinders on that only allow them to see what they want to see. Until they â€Å"crash† into one each other. Crash is the kind of movie that makes you think twice about your actions, asking yourself tough questions, not just of yourself, but of those that are aroun d you; could I have said that differently?Was I acting racist? Do I discriminate against those I do not understand? This is the sort of movie that has us looking deep into ourselves to do some much needed soul-searching. Crash, Boom, Bang Paul Haggis directed â€Å"Crash† with an idea that it not only exposes multi-social, but multicultural differences in order to give us a small window into a few of the interactions and how these interactions, good or bad, affect behaviors and lives, in a relatively small group of individuals.We are allowed to see how this group deals with situations that may be considered to be racially stereotyped and outright prejudiced. Voted the best movie of 2005, by the Academy Awards, â€Å"Crash† as the title implies starts with a crash, but that is only one metaphor for the culture shock that many people have when they ‘crash’ into people from different races, religions, and ethnicities. The city of Los Angeles is shown as a fas t paced place where everything from the people involved in the first interaction to very last gasp of the movie, move faster.The characters seem to speed through their lives, almost unaware and certainly most times without considering the connections and consequences of their daily actions. This is a candid film it clearly shows how a diverse group of individuals when pushed into one another’s lives can leave painful scars in their wake. When you watch Crash you begin to see just how much of what one feels, says, and does can impact so many others around them. There were those however that were shocked by the material covered in it.It can be denied as much as anyone wants to deny it, but the movie is meant to be racist. It was made to make us think about our actions before we open our mouths and insert a foot into it. Some of the aspects in this movie are intended to remind us that no matter how we would like to think that America is a post-discrimination country, the sad tru th is that discrimination and prejudice are far from gone in America. Although this movie opened in 2005, we still have the same problems today.Young Black men are still being stereotyped, as are those of Islam and Latino heritage. Prejudice and discrimination are but two subjects that are covered in this movie. We see from the social stereotyping to the outright racism how painful it must have been for the actors to reach down into themselves and find the emotion needed to do their scenes and do them well enough to make us believe that they were real. Paul Haggis, allows us to see the different layers of the characters as if peeling an onion.Many of us may have pre-assumptions about people from different cultures and how we interact with those people, often under stressful situations. The movie for me was a re-affirmation that all people must be treated with respect at all times. After all it is not their fault that you may be having a bad day, or vice versa. Crash had and has the ability to draw large audiences of different ethnicities, bring them together in one room without fear of arguments. This is partly due to the undercurrents of unacknowledged racism that occurs in American life on an everyday basis.It is the kind of movie that can lead to some soul-searching from its lingering emotional potency. It remains one of the best movies I have even seen. I have always believed that the two most powerful characters in the movie are portrayed by Matt Dillon (Officer John Ryan) and Ryan Phillippe (Officer Tom Hansen). Officer Ryan is not only jaded and abusive, but a racist as well, this is later shown to be because of an ordinance passed by the city of Los Angeles. Officer John Ryan's father loses his business, because most of his employees were working minorities.From that one action we can determine the reason why John becomes a racist individual. This may also be the reason he blames minorities for the closure of his father’s business, thus influenc ing him to mistreat people of other races. This comes to light as Officers Ryan and Hansen pull over a vehicle that is only vaguely similar to the carjacked vehicle that the police are looking for. Officer Ryan mistakenly believes that it is a mixed couple, with the beautiful woman being white; he soon learns that the beautiful woman is in fact a light skinned black woman.The young couple in the vehicle can only wonder what is happening as they see the lights flashing signaling them to pull over. Their confusion turns to fear as Officer Ryan begins to harass them. Instead of speaking up and doing the right thing, Officer Tom Hansen looks on, says nothing to stop it and becomes more dismayed by his partner’s actions by the minute. Officer Ryan, realizing he is in control and that no one is going to stop him; he begins to enjoy his power trip as he roughly handles the slightly tipsy woman.As things progress he does almost everything to Mrs. Thayer except have sex with her as he checks her for weapons as her angered husband can only stand by and watch. Mrs. Thayer’s eyes beg her husband to do something, she sees the anger in his eyes but she also sees fear in his eyes as well. He feels helpless as he sees the fear in hers. These are two white men, two white police men that are in control, however badly, of the situation. He understands the consequences if he makes a move to assist his wife, at best he could be arrested, at worst killed.Another powerful example of poor judgment on Officer Ryan’s part is to never get into a relationship at work is shown when Officer Ryan goes to see Shaniqua Johnson in her office, and has an ulterior motive for seeing her, he wants to enter into a relationship but only to help himself and to possibly get a favor or two later on down the line. From what we have seen so far, we can safely say that Officer Ryan is used to getting his way, becoming angry when he does not, and having his way when it comes to the hav ing the balance of power.However, here we find Officer Ryan in a predicament where, a powerful woman, a powerful black woman, has the upper hand over Officer Ryan. He knows she welds the power as well as she knows who is in control of this situation. She likes being able to give orders and withhold what she knows he wants. It is her choice to make and he does not like it, he can see in her eyes and hear in her tone that this is a futile situation. When she tells him that she will not be able to help his father, he begins his other strategy.Pleading his father’s case and outlining what her actions might cost her in the end; she takes him by surprise and throws him out of her office without helping him. The last time we see Mrs. Thayer she is upside down in a car, having just had an accident and has found herself to be trapped in a vehicle that if she cannot get out of is going to explode and more than likely kill her. Officer Ryan comes upon the accident and calls in for help; meantime he has to get this woman out of the car. Mrs. Thayer recognizes him but the recognition is not mutual. Why this man? She wonders.Is he here just to molest me again? Will he even try to help me out or will he only taunt me as I die? As she begins to weigh the costs and possible benefits of this exchange and what is about to happen she is at once adamantly opposed, and rightly so, to being rescued by a person who, twenty-four hours earlier, had molested her smiling as he did it in from of her husband and not caring who he is as long as he helps her get out of that car. As we look further into this we can see that at first Ryan does not immediately understand why she is so reluctant for him to help her.Slowly recognition kicks in as he recognizes the woman. He does his best to calmly reassure her that he is here to help her that he is the only one here to help her, and the he will not harm her. Again he reassures her that he is only there to help save her and he does finally pull her from the wreckage. We then see as he holds her gently as he calms her that he is not entirely a bad man and that it is possible that his frustrations over not being able to help his father overcame him and turned him into a racist at least up until this point in his life.The most powerful scene that I felt was shown, happened between Officer Hansen and Peter Waters, for me it clearly showed that the balance of power was ambiguous for them both. In this scene we see Officer Hansen, a cop, although an off duty cop, and he feels he holds the balance of power. However Peter Waters does not know that the man he is speaking to is an officer of the law. He believes that he has been picked up by a regular Joe, not a member of the LAPD. It is made clear that Officer Hansen has sized up Peter and made his own observations based on the manner of dress or lack thereof considering the current weather conditions.Officer Hansen’s assessment allows him to correctly assume that this man was up to no good. However, what Officer Hansen does not correctly assess is that Peter is of no threat to his safety. Thinking that he is about to be threatened affects Officer Hansen’s judgment and he mistakenly assumes that Peter is pulling a gun, a tragic mistake that will affect Tom Hansen for the rest of his life. The action also affects Peter’s family as well, they have lost him forever and, in doing so the effect was that Peter, unarmed, was shot and killed.Officer Hansen’s decision was to shoot. But, why would he do that? Police officers are trained to observe minute situations, determine from those observations what their actions and reactions should be. Tom felt that this guy was a bad guy from his observations. If Peter Waters had been pulling a gun out of his pocket, as Officer Hansen mistakenly assumed, then he would definitely benefit the most by acting first. The cost of not acting first could mean death, or at the very least being injured.Re gardless, of the outcome, Officer Hansen correctly identified Peter as a criminal, but his misinterpretation of the situation cost him everything. Although the movie does not tell us what eventually happens to Officer Hansen, we can use our imagination, and assume that his life would have been be changed forever. References: http://academic. udayton. edu/race/01race/whiteness19. htm Crash, DVD, Catalog #17938, Lions Gate Entertainment, 2004, ApolloProScreen GmbH ; Co. http://www. crashfilm. com/ http://en. wikipedia. org/wiki/Crash_(2004_film) http://www. imdb. com/title/tt0375679/fullcredits#cast

Macromolecule Definition and Examples

In chemistry and biology, a  macromolecule is defined as a molecule with a very large number of atoms. Macromolecules typically have more than 100 component atoms. Macromolecules exhibit very different properties from smaller molecules, including their subunits, when applicable. In contrast, a micromolecule is a molecule which has a small size and molecular weight. The term macromolecule was coined by Nobel laureate Hermann Staudinger in the 1920s. At the time, the term polymer had a different meaning than it does today, or else it might have become the preferred word. Macromolecule Examples Most polymers are macromolecules and many biochemical molecules are macromolecules. Polymers consist of subunits, called mers, that are covalently linked to form larger structures. Proteins, DNA, RNA, and plastics are all macromolecules. Many carbohydrates and lipids are macromolecules. Carbon nanotubes are an example of a macromolecule that is not a biological material.

Racial Profiling and Police Brutality Against Hispanics

Police brutality is hardly just a black issue, as  Hispanics all over the country increasingly face police abuse, racial profiling, and  hate crimes. Often this misconduct stems from  xenophobia and rising concerns about undocumented immigrants. Across the nation, police departments have made headlines for their mistreatment of Latinos. These cases have not only involved undocumented immigrants but also Hispanic Americans and permanent legal residents. In states as varied as Connecticut, California, and Arizona, Latinos have suffered at the hands of police in egregious manners. Latinos Targeted in Maricopa County Racial profiling. Unlawful detainment. Stalking. These are some of the inappropriate and illegal behaviors that officers in Arizona have allegedly engaged in, according to a 2012 complaint the U.S. Justice Department filed against the Maricopa County Sheriff’s Office. MCSO deputies  stopped Latino drivers anywhere from four to nine times more than other drivers, in some cases  only to detain them for long periods. In one instance, deputies pulled over a car with four Latino men inside. The driver hadn’t violated any traffic laws, but the officers proceeded to force him and his passengers out of the car and make them wait on the curb, zip-tied, for an hour. The Justice Department also detailed incidents where the authorities  followed Hispanic women to their homes and roughed them up. The federal government alleges that Maricopa County Sheriff Joe Arpaio routinely failed to investigate cases of sexual assault against Hispanic women. The aforementioned cases refer to police interaction with Latinos on the streets of Maricopa County, but inmates in the county jail have also suffered at the hands of law enforcement. Female prisoners have been denied feminine hygiene products  and called derogatory names. Hispanic male inmates have been on the receiving end of racial slurs and put-downs such as â€Å"wetbacks† and â€Å"stupid Mexicans.† Border Patrol Killings It’s not just local law enforcement agencies that have been accused of racially profiling Latinos and committing acts of police brutality against them, it’s also the U.S. Border Patrol. In April 2012, Latino advocacy group Presente.org launched a petition to raise awareness about the Border Patrol’s fatal beating of Anastasio Hernà ¡ndez-Rojas, which took place two years earlier. The group launched the petition after a video of the beating surfaced in hopes of pressuring  the Justice Department to take action against the officers involved. â€Å"If justice isn’t served for Anastasio, even when the video clearly shows injustice, Border Patrol agents will continue their pattern of abuse and lethal force,† the Presente team said in a statement. Between 2010 to 2012, Border Patrol agents were involved in seven killings, according to the civil rights group. LAPD Officer Found Guilty of Profiling Hispanics In an unprecedented move in March 2012, the Los Angeles Police Department determined that one of its officers had engaged in racial profiling. Which group did the officer in question target? Latinos, according to the LAPD. Patrick Smith, a white officer on the job for 15 years, pulled over a disproportionate amount of Latinos during traffic stops, the Los Angeles Times reported. He allegedly tried to conceal the fact that he’d so often targeted Hispanic drivers by misidentifying them as white on paperwork. Smith may be the first LAPD officer found guilty of racial profiling, but he’s unlikely the only one engaging in the practice. â€Å"A 2008 study of LAPD data by a Yale researcher found blacks and Latinos were subjected to stops, frisks, searches, and arrests at significantly higher rates than whites, regardless of whether they lived in high-crime neighborhoods,† the Times noted. Moreover, 250 allegations of racial profiling are made against officers annually. East Haven Police Under Fire News broke in January 2012 that federal investigators had charged police in East Haven, Conn., with obstruction of justice, excessive force, conspiracy and other crimes concerning their treatment of Latinos in the city. According to the New York Times, East Haven police officers, â€Å"stopped and detained people, particularly immigrants, without reason...sometimes slapping, hitting or kicking them when they were handcuffed, and once smashing a mans head into a wall.† They tried to cover up their behavior by targeting bystanders who witnessed and tried to document their illegal acts. They also allegedly tried to recover surveillance tapes from area businesses that captured their abuses on video.