What are the factors that influence effective discharge from hospital Literature review

What are the factors that influence effective discharge from hospital of older people - Literature review Example The discussion aimed at analysing and investigating factors that influence effective discharge from hospital of older people. For this purpose, literature analysis pertaining to the research topic was conducted. After filtering more than 500 research papers of the period 2008-13; a total of 15-20 were selected with the criteria of focusing on the strategies related to the effective discharge of older people. Based on the results, it was found that effective discharge of older people depends on a number of internal and external factors. In this regard, system and healthcare environment, patients’’ knowledge, social factors, healthcare policies, effective communication, and planned policies play an important and decisive role. Additionally, it was found that hospitals need to focus more on understanding the needs and demands of older people and accordingly planning the assessment and discharge policies leading to mutual value. Finally, it was concluded that effective disc harge policies require proper planning, transparent assessment, and effective policies and communication for creating better results. Exclusion criteria were kept simple and precise and thus, articles, research papers, journals, and irrelevant academic books were excluded from the selection criteria. Articles accused of duplication and offering little understanding over the research topic were also not included. Additionally, studies conducted outside the UK and Western countries were also not included in the assessment and analysis process. Articles adding little value in terms of offering information on discharge policies of hospitals were excluded. Information through conferences and other proceedings were not used for the assessment process. 20 Stuen believed that effective discharge is a process used to decide the requirements of patients in terms of moving from one stage to another. In the healthcare industry, effective discharge of

DYADIC RELATIONSHIPS and (B) CHARISMATIC AND TRANSFORMATION LEADERSHIP Case Study - 1

DYADIC RELATIONSHIPS and (B) CHARISMATIC AND TRANSFORMATION LEADERSHIP - Case Study Example e to share their part of version over a particular issue; this gives subordinates confidence and sense of ownership that they are a valuable part of the organisation. And, at the same time, this brings total and practical rather than superficial participation in decision making, besides, this exchange relationship motivates them to avail more subordinate autonomy. In these times, many would not disagree that organisations succeed when they allow their organisational leadership to extend autonomy and ensure the concept of decentralisation aggregately. 2. Comment on â€Å"Dyadic relationships typically progress through a series of ups and downs with shifts in attitudes as the two parties attempt to reconcile their desire for autonomy with their desire for closer involvement† The LMX theory is under-developed. It has yet to fully define the all areas and way exchange relationships evolve over time (Yukl, 2010, p.239). This theory suggests that exchange relationships construct and evolve in a very smooth but continuous fashion, taking their base from the initial impressions. However, some longitudinal studies contend that the LMX relationships develop faster and remain stable. But, other researches do not agree with this claim, they contend that dyadic relationships undergo a series of ups and downs, where roles of behaviours cannot be undermined. The closer elaboration surfaces some facts. Without any doubt, perceptions play a vital role in developing or dissolving any exchange relationships. Many further studies within this area would greatly be helpful in analysing and understanding the each party’s perceptions of the relationships. Charismatic leaders are by nature transformational (Lussier, 2010, p.349). However, not all transformational leaders become successful in achieving their transforming results via the charismatic of their personalities. Charismatic leaders prefer to promote their personal image and identification in contrast to transformational

Spreading Inovation Article Example | Topics and Well Written Essays - 500 words

Spreading Inovation - Article Example The program trains professionals who serve low-income children, mostly in health centers. In the program, health providers are taught how to integrate oral health risk assessment and fluoride varnish applications into services that are usually offered to young children (DHHS, 2012). There are particular main problems that affect the oral health of children. These problems include tooth decay, sucking of the thumb, tongue thrusting, and lip sucking. Although baby teeth will later be replaced with permanent teeth, keeping the teeth of children healthy is critical to their health and well-being (Kramer et al., 2013). The mouth has many bacteria, although most of them are harmless. Good oral health care can help to keep the bacteria at bay. Nonetheless, without appropriate oral hygiene, these bacteria can cause oral infections such as gum disease and tooth decay. Many children, especially in low-income families face the problem of tooth decay, and it is important that they get help in order to overcome these issues (Salem et al., 2012). The Colorado community-based health program is aimed at ensuring that the health care professionals are well-equipped to ensure that children’s oral health is maintained. As the manager of Colorado Health Center, I find â€Å"Cavity Free at Three" program to be a very noble idea. The first step in the introduction of the program to the organization is to offer training for all health professionals that work in the organization. Proper training will ensure that every employee understands the idea behind the innovation in order to implement it. The training will involve explaining to the staff the importance of the program and what the organization aims to achieve. The organization will collaborate with the community and other health organizations in its implementation. In order to maintain the program for a long time, the organization will ensure that it sets aside enough funds to be

Police Administrators Essay Example | Topics and Well Written Essays - 1500 words

Police Administrators - Essay Example Police administrators in the recent past have become aware of their roles both in the community and also in the political arena. Community policing emphasizes on significant changes in approaches of police administrators. Research shows politicians are normally involved in various criminal practices in order to survive in the political arena. Police administrators must walk a fine line as politicians - accepted within their department by police officers - and also answerable to the community. This paper is an exploration of pitfalls and problems of this balancing act. (Dowell, 2004) While police administrators can walk a fine line as politicians, they have to be answerable to the community. This balancing act comes along with problems that may not be very easy to solve. Since time immemorial, politics has been referred to as a dirty game. This is because it is normally associated with crime practices in the society. The problem that comes in when police administrators start involving themselves with politics and at the same time carrying out their responsibilities is that they may not combat some crime issues especially those related to politics. (Kleinman, 2000)This is because there are crime issues that are related to politics that police administrators maybe aware of but due to their political aspirations, in case they deal with them then they may never succeed in the political arena. ... While it may be called a balancing act, in real sense there is lack of proper balance problems that result from this. This is because politicians are normally very busy people with meetings that always go up to late hours in the night. This makes police administrators to spend most of their time carrying out political endeavors. The result is that they fail to attend to their duties as administration officer. One of the roles of administrative officers is to carry out recruitment of junior police officers. (Royster, 1999) Once they get involved in politics they always have to appeal to other politicians by recruiting relatives to other politicians in order to survive in the political arena. This normally results in police administrators taking bribes in their line of duty. It becomes very hard for them to deal with police administrators who are corrupt. This actually results in increase in corruption within a nation. It is very hard to be good and bad at the same time. This is the scenario when police administrators come to the frontline of politics at the same time carry out their responsibilities in the community. When a police administrator carries out his duties in the community concerning crime, he may actually be at conflict with some members of the community and yet expect their approval in the political arena. (Manning, 1985) This is a big problem. Some of the people that carry out crime in the society are people who have political back up and once a police administrator carries out legal measures it follows that he or she will be politically disadvantaged. Another problem that is likely to result from this is in the area of community policing. This could

Stonegate pub company performance Essay Example for Free

Stonegate pub company performance Essay The Stonegate pub company is privately owned which concentrates in pubs and bars in the UK. It was started in the year 2010 and currently have more than 620 bars and pubs all over in the country. In the same year the company acquired over 330 managed pubs from M and B. This gave the company operational power to run. The company takes great care of all its target customers as it has various joints as in: student bars, traditional pubs, night clubs and all kinds of pubs. This makes the company attract all kinds of customers depending on their needs. In 2011, the company joined with the Town and pub company forming a large pub operator which would become the largest in the country. This in return led to the company acquiring lettuce brands, Yate’s and slug. Stonegate company also involves itself in selling of drinks and food that is seasonal favorites. Being one of the largest companies in the country, Stonegate company keeps books of accounts which can be evaluated. The company’s return on capital in the year 2012 is far much higher than that of 2011. This in return has increased the shareholders amount in the year. Since the return on capital in 2012 is greater than in 2011, the company indicated growth. The Gross profit of the company increases from 8.7% to 12.3% due to the increase of sales from 264,671 to 484623. The gross profit of the company indicates that the company is in the right direction towards its development. Net profit margin of any company will show how much it earns after tax deductions per dollar. When it is high, the firm comfortably controls its costs and favorably competes (BAKER, 2005, 62). In 2011 it had 0.41% compared to 4.5% in 2012 and could therefore earn more in 2012 after the tax had been deducted per dollar. The company, hence records higher amount of sale as time goes by. Gearing measures the financial leverage of a company and compares the ration between financial aid by lenders and shareholders. In 2011 it was 47.9% as compared to 159% indicating the country borrowed more than in the previous year. Interest cover shows the ability of a company to repay interest on an outstanding debt. In 2012 the ratio is at 3.5 times as compared with 0.95 in 2011. This indicates the ability of the company to repay has increased. On the other side the company’s current ratio came from 0.77:1 in 2011 to 0.74:1 in 2012. This shows that it was in a position to pay debts comfortably in 2011 while it struggles in 2012 which is not a comfortable place for any company in theworld. Liquidity ratio of a company shows its ability to pay short term debts. Stonegate company had a ratio of 0.69: 1 in 2011 and 0.62: 1 in 2012 showing the ability to repay short term debts reduced in 2012. Stock turnover is the amount of times that stock is sold over a given period of time. The company had a stock turnover of 9 times in 2011 as compared to 6 times in 2012. This indicates that the stock is sold at a fast pace in 2012 as compared to 2011. Debtor collection period is the period in which the business receives money sold on credit. Many businesses sell on credit to increase their sales. In 2011, Stonegate company had a debtor collection period of 43 as compared to 25 in 2012. This shows that the company would be able to get money sold on credit more often in 2012 which leads to development. Credit payment period on the other side represents the number of days a company takes to repay a credit transaction. The shorter the period the busy the business, hence faster development since this indicates faster inflow of cash. In 2011 it was 24 days compared to 12 in 2012. In 2012 therefore, Stonegate company had the power to repay back its debts within half the time spent in the previous year. This indicates growth in financial aspects of the company. The number of days a company takes to realize cash from its inventory is operating ratio. The company has an operating ratio of 28 days in 2011 and 19 days in 2012. The company enjoys fast money in the latter year,which in turn leads to faster development as compared to 2011. Stonegate company compares with other companies in the market and competes effectively. In the year 2011, Net Profit before interest and tax on sales is 0.64% compared to 12.3% in 2012. The company records growth in the latter year as compared to other companies. Labor cost of sales in 2011 is at 26.5% as compared to 28% in the year 2012. In comparison to other companies, the company is paying more of its money in wages and salaries in 2011 than in 2012. This poses dangers in any company. Overhead costs of sales refer to other costs other than labor. These costs may include rent and insurance. In relation to other companies, the company had a figure of 8.2% and 6.7% in 2012 indicating a reduction in the rate of overhead cost. Reduction in overhead costs which may be escapable, benefits the company as it is an additional expense on the side of the company’s budget (Tracy, 2013, 237) . The company’s current ratio in 2011 is at 0.77 and 0.74 in 2012 compared to other companies. This shows lack of strength to pay its debts faster as the years progress. On the side of acid test, the company had a ratio of 0.69: 1 in 2011 and 0.62:1 in 2012. It shows that the company could not comfortably depend on its current asset to pay its current debts in the year 2012 as compared with 2011 in relation to other countries. It therefore shows that the company depends on its own inventory in paying these debts. Stonegate company recorded a favorable rate of stock turnover as compared between the two years 2011 with 9 times and 2012 with 6 times. This shows effective competition with other companies in the market. The company may be lagging behind other companies due to the use of some strategies it takes in its dairy production. The company records tremendous improvement in the financial sector as witnessed by the large amount of profits and sales in 2012 compared to 2011. This shows improvement in the management part of the company which brings aboutbetter methods of production. This is what in return brings the positive change experienced in the company. According to Davenport (2013, p. 27), IT IS due to data-keeping in the company that parties may be able to know where the company is going astray and where they are right. This also helps in decision making . Although the company seems to be walking in the right direction, the business still lags behind other companies in the market due to its strategies. Some of these strategies include gearing. For instance Stonegate company depended much on the lenders as opposed to the shareholders in 2012 as compared to the year 2012. Lenders require a large amount of interests on loans given to the companies and may even ask for repayment within a short period of time (Moles et al, 2011, p. 642). Interests associated with these loans reduces the profit margin as evidenced in the Stonegate company. Other competing companies used the money from the shareholders as this would be somehow permanent as compared to money from the lenders. In this regard, the rate of gearing went up from 47.9 in 2011 to 159 in 2012. This is one of the areas where the company is lagging behind its peers and care must be taken to avoid collapse of the company in the future. The company’s current ratio went down and it could not be able to repay short-term debts as it used to do in the previous year. Decrease in the current ratio of a company may be brought about by such factors as an increase in the amount borrowed reducing the company’s current assets due to repayment of the debts (Kaya Banerjee, 2014, p. 25). Although this money leads to increase in the level of profits, the company should avoid it. Net profit margin, which increases due to this approach helps in the payment of the debt, though it does not fit the amount borrowed. Another rich area that the company is lagging behind is in the payment of wages and salaries. The amount used in 2012 was far much more than the amount spent in the year 2011. This is even after keeping all the other factors constant. Stonegate company’s acid tests proved that it could not depend on its current assets to pay its current liabilities. The company could therefore depend on its inventory to pay these debts.Being unable to pay short term debts by the company is a concern that needs to be addressed in order to prevent collapse of the company.On the other side, the company enjoys improvement in the rate of stock turnover indicating that the products are moving at a higher speed in 2012 compared to 2011. The overhead costs also go down,adding up to the profit margin of the company. Care must be taken to avoid doing away with an overhead cost that is vital to the business for example insurance. This is because overheads costs are an important part in the running of businesses. Stonegate company has adopted strategies that make it compete favorably with other competitors. This has enabled it to remain relevant in the market. It has offered services to all round customers with the number of joints that supply drinks and food. To have powers in the market, the company joined hands with the Town and pub company to form a large company and the largest private company that is in the pub business. It also acquired more than 330 pubs from M and B which gave the company powers to enter the market in full force leading to almost forming a monopoly. In return, Stonegate company has continued to record high amount of profit associated with an increase in the amount of total sales. Due to this factor, it has recorded tremendous development and growth of the structures and the number of workers. An increase in the amount of profits as time goes may be attributed to the increase in the amount of sales sold (Kumar, 2008, p. 62 ). As compared with other companies in both 2011 and 2012, the company records an increase in the amount of profit and sales. This has given the company more resources to deal with the operations of its duties that lead to efficiency and growth. This accounts for the increase in the number of employees’ salaries who increases in number due to increase in the operation of the company. This has in return increased net profit margin of the company showing the positive trend the company is heading to. Rate of stock turnover also reduces in the years under scrutiny. This has led to faster movement in and out of inventory which results in higher returns indicated in the working ratios of the company. The ratio between the shareholders and the lenders also increases during the latter year. This indicates that the company has resulted in the use of the lender’s money as opposed to shareholders’. This in return has made Stonegate company unable to pay short term debts using its current assets since most of its money is borrowed money. This is a major concern for the company to consider and correct. Relying on lenders money may seem risky in the event that they give out money with a lot of requirements that leaves the company in a servant position. The loans also attractthe interest that is additional cost which adds to the expenses of the company in return reducing the profit. Using money from the shareholders who are somehow long time as compared to loans is more easier and efficient. They ask for interests after an agreed period of time without their investment value as opposed to lenders who asks for both (Jiang et al 2010, p. 3602). Stonegate’s debt collection period has reduced in the years in discussion. This indicates good mechanisms and strategies in debt collection and incredit selling. This has enabled the company to reduce its credit repayment period. Managing these important trading strategies by the company has led to growth and improved operations a great achievement in the side of the company and its associates. An area of concern is the ratio of wages and total sales that increased in the year 2012 as compared to 2011. This increase in the ratio indicates that the company would be using more money to pay labor in the latter year as compared to the total output in the same year. This is a point of consideration that Stonebic company should take into account and make the necessary improvements.Stonegate company,continues to report increased revenues as in 2003 it stood at  £470.3m (Wingett Williams, 2014, p. 168). Conclusion             The Stonegate pub company is a competitive company in the market that offers drinks to its esteemed customers. The company keeps records of its finances an indication of a company that follows the set regulations for success in business. The company continues to grow in the amount of sales and profits attributed by the reduction in the rate of stock turnover, debt recollection period and debt repayment period. The company also uses a lot of funds from lenders, which increases its operating capital which in return results in the growth of its structures. The company through its many joints holds all kinds of customers in its different joints as involvement in fresh foods gives it additional customers who do not drink. References Baker, H. K., Powell, G. E. (2005). Understanding Financial Management A Practical Guide. Oxford, Blackwell Pub. Davenport, T. H., Kim, J. (2013). Keeping Up With The Quants: Your Guide To Understanding And Using Analytics Firms, Journal Of Accounting, Business Management, 21, 2, Pp. 23-35 Jiang, W, Li, K, Shao, P 2010, When Shareholders Are Creditors: Effects Of The Simultaneous Holding Of Equity And Debt By Non-Commercial Banking Institutions, Review Of Financial Studies, 23, 10, Pp. 3595-3637 Kaya, H, Banerjee, G 2014, The Impact Of Monetary Policy And Firm Characteristics On Firms Short-Term Assets, Liabilities, Term Structure Of Debt And Liquidity Ratios: Evidence From U.S. Industrial Kumar, V. (2008). Managing Customers For Profit: Strategies To Increase Profits And Build Loyalty. Upper Saddle River, N.J., Wharton School Pub. Moles, P., Parrino, R., Kidwell, D. S. (2011).Corporate Finance. Chichester, Wiley. Tracy, J. A. (2013). Accounting Workbook For Dummies.Hoboken, N.J: John Wiley Sons. Wingett, M, Williams, R. 2014, Stonegate performance in line with peers, Publicans Morning Advertiser. Business Source Complete168, p. 15 Source document

Data Gathering And Dissemination In Wireless

Data Gathering And Dissemination In Wireless A wireless sensor network is special kind of ad hoc networks that consists of a number of low-cost, low-power, and multi-functional wireless sensor nodes, with sensing, wireless communications and computation capabilities [1,2,3]. These sensor nodes communicate over a short range via a wireless medium and collaborate to accomplish a common task, like environmental monitoring, military surveillance, and industrial process control [3]. Wireless sensor networks have open up for new opportunities to observe and interact with the physical environment around us. They enable us now to collect and gather data that was difficult or impossible before [4]. Although Wireless Sensor Networks have given new ways to provide information from variety of applications, irrespective of the nature of physical environment, it is seen as a challenging task to extract data from sensor network. Data dissemination and gathering are two terms used in sensor networks to describe two categories of data handling methods. Data dissemination is a process by which data and queries for data are routed in the sensor networks where as data gathering is to transmit data that has been collected by the sensor nodes to the base stations. Data gathering protocols aim to minimize the energy consumption and delay of data gathering process [5]. Although there are differences between these two but almost all the literature called together as routing protocols. Unlike traditional wireless communications networks such as mobile ad hoc and cellular systems, wireless sensor networks have the following unique characteristics and constraints [3]: high density sensor node deployment, battery or no power sensor nodes, low memory and processor capacity, self-configurable, unreliable sensor nodes, data redundancy, application specific and dynamic topology. Due to above characteristics and constraints of wireless sensor networks, the extraction of data from the network is always a challenge. Therefore, it is importa nt that the design of protocols for data gathering and dissemination takes care about these challenges. The main design challenges of routing protocols for wireless sensor network are: Energy, Processing power and Memory. Some of the design challenges as reflected in [3, 6] are highlighted below: Large number of sensor nodes: Since most of the wireless sensor networks composed of large sensor nodes, it is very difficult to have an addressing scheme like other wireless networks. The traditional IP scheme is not feasible to apply for wireless sensor networks. Moreover, the sensor nodes are deployed at random in hostile environment. Limited energy capacity: The sensor nodes are battery powered, so they have limited energy. This is the main challenges in designing wireless sensor networks. In practice, sensor network deployment makes sense only if they can run unattended for months and years without running short of energy [4]. Flow of Data: Almost all the applications of sensor network require the sensory data from multiple sources to flow towards a single destination node called sink in contrast to the traditional networks. Sensor node locations: Most of the proposed routing protocols assumed that the sensor nodes are equipped with global positioning system (GPS), but in practice it is very difficult to manage the locations of sensor nodes. It has become more challenging as sensor networks topology changes frequently due to node failures, moving from the coverage area. Data redundancy: Data collected by various sensor nodes are typically based on common phenomenon; hence the probability of data redundancy is very high. The routing protocol needs to incorporate data aggregation techniques to decrease the number of transmission. Application Specific: The sensor networks are application specific. The requirement of routing protocol changes as per the specific application. It is very challenging to design routing protocols which can meet the requirements of all applications. Scalability: The size of the network grows, so the routing protocols need to be scalable to support the addition of sensor nodes. All sensors may not necessarily have same capabilities of energy, processing, sensing and communications. These should be taken care while designing the routing protocols. Addition to the above parameters the designing of routing protocols for wireless sensor networks also need to look into following points [6]: Node deployment Related work: Since wireless sensor networks gain its usage in various application areas, there is a growing interest in this field leading towards continual emergence of new architectural techniques. Wireless sensor network is widely considered as one of the most important technologies of the 21st century [8]. In this section we bring out and highlight how our survey differs from the similar surveys done previously in this area. We also highlight the scope and target group who will benefit from our work. In [2], similar survey was carried out on routing protocols for wireless networks. The information in [2] was published some five years back and many new protocols have not covered. In [3], although it has covered almost all the routing protocols for wireless sensor networks but it does not provide insight knowledge about the protocols. The survey is good for readers interested in broad area. The goal of [8] is to give a comprehensive survey on routing techniques focusing on mobility issues in sensor networks and does not cover all the routing protocols in wireless sensor networks. In this survey, we bring out the comparative study among wireless sensor network routing protocols bringing their differences and similarities. We also bring out the advantages and disadvantages of different protocols to use in different applications of wireless sensor networks. This survey would be useful for both introductory readers as well as for aspirant researchers who would like to get the comprehen sive idea about the current-state-of-art regarding the techniques of data gathering and dissemination in wireless sensor networks. However, we follow [3] in classifying the routing protocols into different categories although we put some additional protocols which are not covered by [3]. We also excluded multipath-based protocol category since it falls under data-centric category. Table 1 shows the different categories of wireless sensor network routing protocols inspired by [3]. The representative protocols with (*) marks are our additions. Table 1: Routing Protocols for WSNs Category of Protocols Representative Protocol Location-based Protocols MECN, SMECN,GAF, GEAR, Span, TBF, BVGF, GeRaF Data-centric Protocols SPIN, Directed Diffusion, Rumor Routing, COUGAR, EAD, ACQUIRE, Information-Directed Routing, Gradient-based Routing, Energy-aware routing, Information Directed Routing, Quorum-based Information dissemination, Home Agent-based Information Dissemination, *Flooding, *Gossiping. Hierarchical-based Protocols LEACH, PEGASIS, HEED, TEEN, APTEEN Mobility-based Protocols SEAD, TTDD, Joint mobility and routing, Data MULES, Dynamic Proxy Tree-based Data Dissemination, *MDC Heterogeneity-based Protocols IDSQ,CADR,CHR QoS-based Protocols SAR, SPEED, Energy-Aware Routing. Data-Centric Protocols The protocols are differentiated into two categories called data-centric and address-centric. The address-centric routing protocols find the shortest path between source and the destination with addressing scheme like IP whereas in data-centric routing protocols focus is made to search routes from multiple source nodes to a single destination node. In the sensor networks, data-centric routing is preferred where data consolidation and aggregation is done by the intermediate nodes on the data coming from multiple sources before sending to the sink node. This way, it saves some energy preventing redundant data transmissions. In this section, we highlight some of the samples of data-centric routing protocols proposed for wireless sensor networks. Flooding: Flooding [5] is a data dissemination method where each sensor node that receives a packet broadcasts it to its neighboring nodes assuming that node itself is not the destination of the packet. This process continues until the packet arrives the destination or the maximum hop counts for that packet is reached. Flooding though is a simple and easy to implement, but it has problem like implosion (duplicate message sent to the same node) and overlap (duplicate message receive by the same node) [2]. Figure 1 and 2 reproduced from [2] shows the implosion and overlap problems in flooding. Gossiping: Gossiping [5] is based on flooding, but nodes that receives the packet forwards it only to a single randomly selected neighbor. It avoids implosion problem of flooding and it does not waste as much network resources as flooding. However, gossiping is not a reliable data dissemination method since the neighbor node is selected at random, some nodes may not receive that message at all. Moreover, it introduces a delay in propagation of data through the nodes [2] since all the nodes which forwards or sends data need to select a node. SPIN: Sensor Protocols for Information via Negotiation (SPIN) [9, 10] aims to improve the implosion and overlapping problems of classic flooding protocol. The SPIN protocols are based on two key mechanisms namely negotiation and resource adaptation [3]. It uses three types of messages [5]: ADV, REQ, and DATA. The sensor node which has collected data sends an ADV message using high-level descriptors or meta-data regarding the actual data. The actual data is transmitted only when the REQ message is received from the interested nodes. This negotiation mechanism avoids the overlapping and implosion problems of classic flooding because the REQ message is sent from the interested node only when it does not have that data. Fig. 3, redrawn from [5] shows how these three messages are exchanged and fig. 4 inspired by [9] and reproduced from [11] shows more detail process who SPIN works. There are about four versions of SPIN protocols [6, 9, 10]. They are SPIN-PP, SPIN-BC, SPIN-EC and SPIN-RL. Both SIPN-PP and SPIN-BC works under ideal condition when energy is not constraint and packet are never lost. SPIN-PP tackles the data dissemination problem by using point to point media where as SPIN-BC uses broadcast media. There other two protocols are the modified versions of SPIN-PP and SPIN-BC in order to network which are not ideal. SPIN-EC is actually SPIN-PP with additional energy conservation capability. Under SPIN-EC, the nodes participate in data dissemination only when it computes that it has enough energy. If the node has plentiful energy, it works as same as SPIN-PP with 3-stage handshake. SPIN-RL is a version of SPIN-BC which tries to recover from the losses in the network by selectively retransmitting the messages. In SPIN topological changes are localized as each node needs to have information of their next immediate one-hop neighbor only. But this type of protocol cannot be used in applications where reliability is of greater concern like forest fire and intrusion detection since it does not guarantee the data delivery [2]. If the nodes that are interested in data are located far way and the intermediate nodes are not interested then the ADV message will not received which in turn will not able to get data. Directed Diffusion: Directed Diffusion [12] consists of elements like interests, data, messages, gradients and reinforcements. The main objective of the protocol is to use naming scheme to reduce the energy usage by avoiding unnecessary routing operations. Interest is a query or interrogation on what user wants and it contains descriptions of a sensing task. Data is the collected or processed information of a physical phenomenon which is named using attribute-value pair. Gradient is a link a neighbor from which interest was received, and it is characterized by data rate, duration, and expiration time which has derived from the received interest filed [2]. A node, usually sink will be broadcasting interest to request data by diffusing interest through its neighbors. The interests are periodically refreshed by the sink. When this interest is received by the intermediate nodes, they cache for future use, or do in-network data aggregation or direct interest based on previous cached data. The source node sen ds the data back through the reverse path of the interest. When data is received by the nodes, they try to compare with the interest cache before. The data which matches the interest is drawn and then sent via the same path where the interest has received. Out of several paths between sink and the source, one path is selected by network by reinforcement. Once this path is selected, the sink sends the original interest again with smaller time interval so as to make the source node on the selected path to send data more frequently. Although directed diffusion has advantages that the protocol can in-network data aggregation and caching which saves energy but this protocol cannot not be applicable to all the applications of wireless sensor networks. The protocol can only be applied to such application which is query driven. It is not suitable for the applications such as forest fire detection or intrusion detection. Fig. 4, copied from [12] shows the working of the protocol. Rumor Routing Rumor routing [13] another variation of Directed Diffusion aims to direct the query to the nodes which have observed event rather than flooding the entire network [2]. It is a logical compromise between query flooding and event flooding [3]. This protocol is only useful if the number of queries compared to number of events is between the two interaction points. See fig. 5, redrawn from [13]. Rumor routing algorithms introduces an agent, a long live packet. An agent, which also contains an event table like nodes, travels the network propagating information about local event to the distant nodes. The agent informs the nodes it encounters of any events it has observed on its way and at the same time it will synchronize its event table with the event table of encountered node. An agent will travel the network for certain number of hops and then die. All the nodes including an agent maintains an event table list that has event-distance pairs, as shown in fig. 6, copied from [13]. So when a node generates a query for an event, the nodes that knows the route, can respond to the query by referring its event table [2]. In this way, flooding the whole network is avoided. Directional rumor routing is proposed in [14], which try to improve latency and energy consumption by considering query and event propagation in straight line instead of random walk in normal rumor routing. Cougar Cougar [15, 16] is a database approach for tasking sensor networks through declarative queries. Since in-network computation is much cheaper than transmission and communication between nodes, cougar approach proposes a loosely-coupled distributed architecture to support both aggregation and in-network computation. This helps in reducing energy consumption thereby increasing lifetime. The architecture introduces a query proxy layer in each sensor node which interacts both with network layer and application layers. The gateway node (where query optimizer is located) generates a query processing plan after receiving queries from the sensor nodes. This query plan specifies both data flow between sensor nodes and in-network computation plan at each individual sensor node. The query plan also contains how to select a leader for the query. The query plan can be viewed at non-leader node and at the leader node. Fig. 7 and fig. 8, redrawn from [15], show query plan at non-leader node (source sensor) and leader node respectively. Although, cougar provides solution to interact with the sensor nodes independent from the network layer, but the insertion of proxy layer at each sensor node introduce extra overhead for sensor node in terms of memory and energy consumption [2]. Additional delay may be incurred with the relay trying to wait for the packets from other nodes for aggregation before sending to the leader node. ACQUIRE ACQUIRE [16] is a data-centric routing protocol aiming at large distributed databases. It aims at complex queries which comprise of several sub-queries that are combined by conjunctions or disjunctions in an arbitrary manner. The protocol sends an active query packet into the network. This active query packet is sent by the sink, which takes random path or path predefined or guided. The node which receives this active query packet uses information stored within them to partially resolve the query. If the nodes do not have updated information, they gather the information from their neighboring nodes with the distance of d (look-ahead parameter) hops. When the active query is resolved completely, the response is sent back to the node which has issued the query. Some of the assumptions made in this protocol are [17]: the sensors, with same transmission range are laid out uniformly in a region and they are stationary and do not fail. EAD: Energy-Aware Data-Centric Routing Energy-Aware Data-Centric (EAD) [18] aims to construct a virtual backbone containing all active sensors, which is responsible for in-network data processing and relaying traffic. The radios of other nodes which are not in the virtual backbone are put off to conserve the energy. The sensor network is represented by a broadcast tree rooted at the gateway and spanning all the sensors with large leaf nodes. In order to conserve power, the radios of these leaf nodes are put off while the nodes which are in virtual backbone are active for traffic relaying. The protocol tries to construct broadcast spanning tree network with maximum leaf nodes so that maximum energy can be conserved. The concept of EAD is to include the neighboring broadcast scheduling and the distributed competition among neighbors, based on residual energy [18]. The efficiency of the protocol would be more when the size of the network is small. When the size of the network is large, execution time will be more since the e xecution process propagates from the sink to the whole network. Other protocol like the one proposed by Shah and Rabaey in [19] also aims at increasing network life time. They use network survivability as the main metric and propose to choose one of the multiple paths with a certain probability so that the whole network life time increases. But the protocol assumes that each node is addressable with some addressing schemes. Information-Directed Routing Location-based Protocols Since sensor nodes have limited energy capacity, most of the routing protocols aim to reduce the consumption of energy in routing processes. In most of the protocols location of the sensor nodes are used to find the distance between two communicating pairs in order to find the best possible path with low energy usage. If location of a particular sensor node is known, query can be sent to that particular location only without sending to other regions which will reduce the number of transmission significantly [2]. Location-based protocol makes use of the position information to relay data to the network rather than the whole network. In this section, we describe some of the location-based routing protocols proposed for wireless sensor networks. Minimum Energy Communication Network (MECN): Hierarchical-based Protocols

The Road Not Taken Essay examples -- Literary Analysis, Robert Frost

Robert Frost’s â€Å"The Road Not Taken† has touched the hearts of people all over America and has rightfully earned its place in the American literary canon. Written in 1916 by one of the greatest poets in American history; Robert Frost uses an unique metrical form that brings nature to life and a gives the reader a firm understanding of the rural lifestyle. Inspired by his friend Edward Thomas, Robert Frost’s â€Å"The Road Not Taken† pits a man against two paths for which a difficult choice must be made. After that man makes his choice he tells the reader â€Å"Two roads diverged in a wood, and I— I took the one less traveled by, and that has made all the difference† (Frost). The man does not reveal whether he made the right choice; all he tells the reader is that his choice made a significant impact on his life. For decades, various literary critics have analyzed this piece of writing trying to uncover its true meaning. Many scholars hav e found this piece to be a truly inspirational work while others have pictured it nothing more than an ironic tale of right and wrong. Alexander Meiklejohn is one scholar who used Robert Frost’s poem to teach others about making the right choices. Katherine Kearns, on the other hand, feels that the poem does not live up to its popularity. The viewpoints and criticisms regarding this unique piece of literature stretch far and wide, proving that Robert Frost’s poem has intrigued readers for decades. A large volume of criticisms have emerged that offer new perspectives for readers to explore as they continue to read â€Å"The Road Not Taken† for decades to come. Alexander Meiklejohn found Frost’s poem to be a truly inspirational work. Meiklejohn was a philosopher and well-educated teacher. His views on life refl... ...terpretations of the story will vary. Robert Faggen takes this criticism a step further and relates the poem to Charles Darwin’s theory of evolution and how species evolved by making difficult choices through their existence. Karen Kearns represents those critics who do not feel strongly about Robert Frost’s poem. Though many critics can agree Robert Frost’s poem illustrates various levels of irony; Kearns finds it ironic that â€Å"The Road not Taken†, a mediocre poem at best, is being regarded as one of the most popular poems in the American literary canon. The criticisms for this poem will never end as long as people continue to make difficult choices in their lives. After reading the â€Å"The Road not Taken,† one can form their own criticisms about what path is right for them; whether it means taking the road bent in the undergrowth or embarking on the road not taken.