Modern Trends in Hf Communication free essay sample

Even today, entire frequency spectrum of VLF, LF, HF, VHF, and UHF, as well as UHF, SHF and soon also EHF SATCOM is used to set up communication with units and forces at sea. Which of these transmission media is selected depends mainly on the availability of the information channel in terms of coverage range, transmission speed and, last but not the least, required data rate. However, the decisive factor is, and will continue to be, the geographical distance to the receiving station. We can distinguish between three such distances as line of sight (LOS), extended line of sight (ELOS), up to approximately 300 NM and beyond line of sight (BLOS) for coverage beyond 300 NM. Two viable options available for communication beyond line of sight and worldwide are following: †¢ High Frequency Communication (2 to 30 MHz) †¢ Satellite Communication HF COMMUNICATION [pic] The key benefit of HF Radio is that it provides communication over very long distances (worldwide with a suitable aerial). It achieves this with sky wave communication, where the HF signal is reflected off the ionosphere (illustrated above) for long distance communication, or using Near Vertical Incidence Skywave (NVIS) for shorter distances. This benefit comes with a number of drawbacks: †¢ Slow speed. Rates vary from 75 to 12,800 bits per second, with 1,200 bits per second typical. This is insufficient to support many desirable applications. †¢ Cannot send and receive at the same time. †¢ The equipment (radios, modems, batteries, and antenna) is large and heavy. A small system with a whip antenna will weigh several kilograms. Transmission can suffer from noise and errors. Transmissions at radio frequencies higher than HF (VHF, UHF, EHF, SHF) overcome all of the drawbacks of HF, and can provide high bandwidth data communications enabling key communication capabilities. The main restriction of all of these frequencies is that they are limited to line of sight. For some technologies, dista nce more than line of sight can be achieved by use of a slightly curved communications path. This gives a little extra distance, but distance is still a key constraint. SATELLITE Satellite communication is becoming the preferred choice for long distance communication, offering relatively high bandwidth. However, there are a number of drawbacks: †¢ Area coverage of a given satellite or satellite system is often constrained, and may not provide what is needed. †¢ Satellites are expensive. †¢ Military satellite terminals are quite a bit larger and heavier than HF radios. Some commercial terminals are smaller †¢ Satellite will not work in all terrain for example it is not suitable in jungle. National control may be an issue for countries that cannot afford their own satellite systems, and need to rely on commercial or foreign systems. †¢ Satellite ground stations are subject to jamming and other threats. †¢ The satellite is vulnerable single point of failure. Chinas January 2007 demonstration of its anti-satellite capabilities is clear evidence of their vulnerability. Satellites are also potentially vulnerable to attack by laser or EMP (electromagnetic pulse). Many countries are not capable of maintenance, fault identification and rectification of satellite space segments Keeping in mind the aforesaid for the military in many nations, if not in all nations, HF is a primary means of communications rather than a backup. In some countries no other communication techniques are contemplated for such services as ship to shore or aircraft to ground over distances beyond line of site. The vulnerability of satellites makes nations consider HF communications as a primary military communication medium even when satellites are part of their military operations. This paper will provide an introduction to HF communications in general and the limitations of traditional HF radio systems. It will then explore the significant improvements in capability and performance that the exploitation of modem technology has made possible. in particular the impact of Adaptive techniques, hardware advancements and signal processing CHAPTER II MILITARY SYSTEM REQUIREMENTS The requirements of a military system range from repetitive broadcasts of simple commands on teletype to secure digital communications. Global operations demand the HF system adapt to propagation conditions in regions varying from equatorial to polar. Each area has its separate propagation problems and there may be a need to tailor systems to propagation requirements of the area. In the architecture of military systems there are operational requirements as follows: †¢ Connectiveness:The requirements may range from point to point or broadcasting †¢ Master station:In almost all cases a master station is contemplated with command headquarters organizing the distribution of the system. In this case multiple networks are needed to allow communications within limited groups. †¢ Relay:Relay may consist of rebroadcasting or rerouting. Path diversity, i. e. moving a signal to a path with minimum propagation outages is an area on which military research and development must concentrate. †¢ Identification:To identify the type, security and range etc of communication The technical requirements from users include many items. While the list may seem to be a wish list, firm needs can be shown in each of the following areas: Voice †¢ Data †¢ Adequate anti-jam margin †¢ Security †¢ Interoperability †¢ Coverage: ground and skywave †¢ Channel optimization †¢ Message error control CHAPTER III HF COMMUNICATION High frequency (HF) radio provides an effective means of communication over long distance oceanic. HF communication is no longer restricted to voice and is undergoing a resurgence of interest due to the need to find a means of long distance data communication that will augment and replace existing VHF and SATCOM data links. HF RANGE AND PROPAGATION In the HF range (2 MHz to 30 MHz) radio waves propagate over long distances due to reflection from the ionized layers in the upper atmosphere. Due to variations in height and intensities of the ionized regions, different frequencies must be used at different times of day and night and for different paths. There is also some seasonal variation (particularly between winter and summer). Propagation may also be disturbed and enhanced during periods of intense solar activity. The upshot of this is that HF propagation has considerable vagaries and is far less predictable than propagation at VHF. SSB MODULATION The spectrum available for HF communication is extremely limited. As a result, steps are taken to restrict the bandwidth of transmitted signals, for both voice and data. Double sideband (DSB) amplitude modulation requires a bandwidth of at least 7 kHz but this can be reduced by transmitting only one of the two sidebands. Note that either the upper sideband (USB) or the lower sideband (LSB) can be used because they both contain the same modulating signal information. In addition, it is possible to reduce (or ‘suppress’) the carrier as this, in itself, does not convey any information. In order to demodulate a signal transmitted without a carrier it is necessary to reinsert the carrier at the receiving end (this is done in the demodulator stage where a beat frequency oscillator or carrier insertion oscillator replaces the missing carrier signal at the final intermediate frequency. The absence of the carrier means that less power is wasted in the transmitter which consequently operates at significantly higher efficiency. Figure 3. 1 shows the frequency spectrum of an RF signal using different types of amplitude modulation, with and without a carrier. In Figure 3. 1(a) the mode of transmission is conventional double sideband (DSB) amplitude modulation with full-carrier. Figure 3. 1(b) shows the effect of suppressing the carrier. This type of modulation is known as double sideband suppressed-carrier (DSB-SC). In practical DSB-SC systems the level of the carrier is typically reduced by 30 dB, or more. The DSB-SC signal has the same overall bandwidth as the DSB full-carrier signal but the reduction in carrier results in improved efficiency as well as reduced susceptibility to heterodyne interference. Figure 3. (c) shows the effect of removing both the carrier and the upper sideband. The resulting signal is referred to as single sideband (SSB), in this case using only the lower sideband (LSB). Note how the overall bandwidth has been reduced to only around 3. 5 kHz, i. e. half that of the comparable DSB AM signal shown in Figure 3. 1(a). IMPACT OF MODERN TECHNOLOGY Due to the accelerated development of systems using satellites, high fr equency (HF) systems were in a recession for almost a decade. Now, we are witnessing a forceful comeback of HF systems in civilian and military sectors. The fundamental problem other than as discussed in chapter I related to the achievement and maintenance of a good quality HF communication circuit is associated with the inherent dynamics of the HF link. Conditions over the link may change rapidly, the communication system must be able to adapt to the prevailing nditions. The dynamic nature of the HF medium necessitates the use of a fast processing capability to optimize the system performance. Digital radio frequency and control system technology together with a cheap and reliable fast processing capability combine to address the HF problem in achievable way. Digital control system provides the nervous system for modern HF system designs. They can orchestrate automatic adaptation, timing, frequency hopping, radiated power level control, information flow control and other control functions required in a modern HF adaptive system. Techniques for real time frequency management are now being implemented in current systems. The impact of Very Large Scale Integration (VLSI) will be evident in all types of future communication system. VLSI technology provide the ability to reduce size, weight and power consumption of existing equipment and to increase the overall system reliability. It is enables more complex systems to be provided by introducing techniques and applications which have not previously been possible because of the lack of necessary technology. Highly reliable HF systems are dependent upon efficient signal processing. Sophisticated digital signal processing has made new modulation modes practicable, whilst at the same time reducing the equipment cost. Such techniques operate on the modulating signal or on the RF carrier in a manner which increase the quality of intelligence transferred from the sender to the receiver. VLSI techniques enable sophisticated modulation and coding to be implemented; high levels of data interleaving can be used to overcome the effect of burst errors. Digital modems are adaptable to different modes by software techniques, avoiding hardware retrofits or conversations. The modulation and demodulation process can now be performing digitally. Wideband modulation schemes and frequency hopping techniques are becoming more common; digital control synthesizers are capable of changing frequencies many times a seconds. Voice processing and speech recognition techniques enable limited vocabulary speech to be transmitted over a narrow bandwidth. Applications that rely upon fast processing of voice signals demand the use of filters that can provide high stability and performance. This can be achieved through the use of VLSI technology in the implementation of digital filters. Progress in VLSI techniques is such that integrated receivers front ends, incorporating frequency changers and IF amplifiers, are already feasible. Future development may lead to direct analog to digital conversion of RF signals with high rate conversion. Problems of dynamic range, inter-modulation and conversion speeds remain to be overcome. The use of electronically steered receiving antennas arrays is also made feasible by the use of VLSI techniques which are able to provide the processing power necessary to perform efficient wave front analysis. Evolving equipment designed to meet continuing needs has yielded significant improvement of receivers, trans receivers, and input/output devices. Equipment that relieves onerous tasks such as radio tuning and radio monitoring is now popular. The technical challenge has been to obtain electronic control without losing the performance available from the best manual equipment. While digital technology will assume some of the hardware burden, high power and high frequency analog circuitry will still be required. The key thrusts are in tuning speed, spectral purity and system bandwidth. Fault detection and diagnosis can be improved using processor waste monitoring, control system and built in test (BITE). These enable online systems tests to be automatic and repeated on a frequent basis to indicate potential problems before they become serious. Even greater capabilities will result form a signal processing power of very high speed integrated circuitry (VHSIC) technology. The associated speed and processing power will replace additional circuit boards of analog components in the processing of still more sophisticated waveforms. The trend will continue with digital embedding of present day function such as artificial intelligence based control and cryptographic facilities. The scope for technology improves HF communication systems appeared to be considerable. In the following chapters some of the principal trends of future HF communication systems will be discussed. These advanced techniques, as already evident from the aforesaid brief overview, cover a wide range of technical innovation. CHAPTER IV REAL TIME CHANNEL EVALUATION THE CONCEPTS OF REAL TIME CHANNEL EVALUATION (RTCE) Certainly the cornerstone of advanced HF communications is the concept of evaluation in real time of the interference and propagation problems of the circuit and dealing with them, automatically. The basic systems are of the open and closed loop varieties. The open loop has no feedback path and the closed loop does. For a broadcast an open loop might do; for two way communications it will not. Probably the most advanced form of RTCE is that of an adaptive system whose parameters can change in response to changes in available capacity. Even if constant rate transmission is mandatory the source and channel encoding procedures must be made adaptive to counter changes in the received SNR. Added redundancy for example when there are losses in propagation must form part of the system. From this concept there must be system control strategies. The provision of a high integrity engineering order wire facility is vital. Continuous checking of traffic quality must be made with automatic repeat request techniques. The source encoder must be able to compress or modify the basic source data. ASPECTS OF REAL TIME CHANNEL EVALUATION The general principles of RTCE are in place; what are the possible means of implementing it? , the real time oblique ionospheric sounding could be a portion of the channel evaluation to be performed, similar to that made by an ionospheric oblique sounder. A waveform could be generated for channel evaluation. During the pause of the emissions, measurements of noise and interference could be performed at both the master and the slave station of the link. After processing the small group of available frequencies could be chosen. The initial band of frequencies is to be probed for a particular time and circuit could be performed by simplified algorithms or tables for certain sites and times. Within the possible bands the precise frequencies would be sampled to determine optimum transmission parameters. The properties of the path which are monitored include: †¢ Noise and interference spectral density †¢ (Signal + Noise) level †¢ Multipath spread †¢ Doppler spread The measurement of the properties of a communication channel is particularly important in digital communications because high-speed data transmission critically depends upon them. The measurements in levels of increasing complexity are: †¢ Measurement of multipath spread and Doppler spread; Doppler shift and spectral skewness. †¢ Measurement of second-order channel functions. †¢ Measurement of instantaneous channel functions. For the parameters above, measurement techniques used are based upon differentiation, level crossing and correlation. For the second item, the techniques used are correlation techniques, multitone approach, pulse pair method and chirp technique. For the measurement of the parameters in item 3, the methods used are cross correlation, multitone, and pulsepair. CHAPTER V CODING With the digitization of HF came the need for coding for both error correction and security. With its heavy burden of propagation problems, coding represented for HF a means of facing problems in a particular environment and for distinctive conditions. However coding also provides a means for boosting the data rate in a channel towards the theoretical limit established by Shannon for that channel. Linear block codes (of which cyclic codes are a subclass) and convolutional codes are the main categories of codes of interest to HF communications. They are capable of correcting random errors due to white Gaussian noise as well as burst errors due to impulse noise. In block codes, a block of information bits is followed by a group of check bits. The latter verify the presence of errors in the former. At the receiving terminal the check bits are used to verify the information bits in the block immediately preceding the check bits. There are various classes of block codes including hamming codes which require a minimum number of bits for correction of single errors, cyclic codes which have ease of implementation, ability to correct large numbers of random errors, long bursts of errors and loss of synchronization. In convolutional codes, check bits are continuously interleaved with information bits and they check the presence of errors not only in the block immediately preceding them, but in other blocks as well. It has become feasible to mechanize coders and decoders that are known from theoretical work to be optimum and units have entered the field of HF communications. In practice convolutional codes are used mostly for error correction. Most of the coding applications to HF communications have consisted of error correction through the use of parity checks and of automatic error correction by retransmission. One of the main purposes of error correction is to reduce the effects of long deep fades. Very long recurrent codes or short codes with a considerable number of interleaved blocks can be used. Time delays of 1 to 2 seconds are experienced with decoding. Code rates between 1/2 and 4/5 are used if what is required is only error detection. The use of coding is expanding with the availability of inexpensive off the shelf computers. Its extensive use is vital to combat the problems of propagation and interference, and to allow for secure communications. CHAPTER VI EQUIPMENT ADVANCES Significant improvement has been made through electronic control. In addition to the obvious advantages of digitization, this reduces the use of highly trained operators and allows for automatic equipment testing. RECEIVERS The current dominant performance improvement in receiver design has involved decreasing the unwanted products from the front-end converter. LO synthesizer phase noise is now the dominant deterrent to discriminating against a strong adjacent signal. A strong signal acts as a local oscillator. LO phase-lock-loop synthesizers are an economic compromise between tuning speed and phase noise. The industry now perceives the economic and performance advantages to digital implementation of selective filters, demodulators, and automatic gain control with many parameters such as amplitude and phase characteristics as stable as the logic clock drive. There are now available for example commercial digital signal processing chips and boards. Receivers are more frequency agile than transmitters; surveillance receivers at control centers can automatically monitor channel occupancy and potential interference. Operational convenience of the new receivers includes function control by microprocessors at remote locations and built in test equipment. TRANSCEIVERS AND ANTENNA COUPLERS New transceivers are following the lead of digitally controlled receivers; they are designed at the present primarily for the SSB modulation voice bandwidth channel. Remote controlled receivers can solve the problem of limited cockpit space, manpack use without removing the pack, and remote placing of equipment in tactical ground vehicles. AUDIO AND DATA CHANNEL PERIPHERALS While the audio modem is a de facto standard, two notable input/output devices are now being developed. They are the small data terminal and the secure voice terminal. There is no concensus on modem design. There are unique HF low data rate modems but without interoperability. There are indications of strong competition for 2400-bps modems offering enhanced performance. Serial modems are vying with parallel modems; national extensive tests are needed to adopt a standard unit. In the field, handheld terminals substitute for teletype equipment and computer terminals. They allow off-line composition and editing before transmission at teletype or burst rates. Internal simple FSK models are typical. Demodulation, storage and display complete their capabilities. Most use typewriter keyboards. HF modems for high speed data such as 2400bps digitized voice have evolved toward multipletone signaling carrying differential phase shift keying. Parallel tones having durations much longer than the expected multipath delays are favored, even though parallel channels have been an expensive implementation. Digital data processing has now minimized the parallel channel cost penalty. MODEMS Both theoretical and experimental aspects of modems were considered by Monsen. He found that combined modulation and coding techniques can remove much of the fading effect even in high data applications where intersymbol interference is a serious problem. Experimental results for various models were compared. Successful communication was achieved using equalizer modems in a high data rate application. Monsen emphasized the importance of delay in producing high quality communications-if delay can be tolerated the capabilities of HF can be enormously increased. CHAPTER VII PROPAGATION In HF communications, the ionosphere must be listed as a black box along with transmitter, encoder, antenna, and receiver. The abandonment of HF as a vital portion of modern communication resources is due in part to the difficulties of dealing with the ionosphere. HFs most vital problem as a modern communication system will remain propagation. THE PROBLEMS †¢ Multipath propagation with different time delays, amplitudes and polarizations will distort the signal, producing fading which might not be correlated even within a 3kHz bandwidth. Digital transmission is particularly affected by fading even for time delay differences as short as 50 us (path length difference of 15 km). †¢ Ionospheric tilts. Horizontal gradients both large and small scale make it difficult to model a propagation path because the ionosphere changes with time and with both latitude and longitude. †¢ The effects of irregularities. Irregularities acting as scatters produce rapid and slow fading. Sporadic E or highly ionized regions at about 100 km with relatively small extent produce unusual propagation. For HF the fluctuations are primarily from small scale irregularities in the F layer. F layer irregularities produce rapid fading of HF signals both in the equatorial, auroral and polar areas. Mid-latitude irregularities can on occasion produce serious fading on HF signals. These, however, are problems which can be dealt with by means of coding and error correcting codes. THE LASTING PROBLEMS The problems which any HF system must deal with are problems resulting from geophysical disturbances. Solar flares with particular characteristics and magnetic sector changes on the sun produce ionospheric disturbances. †¢ A direct solar flare effect is the sudden ionospheric disturbance-blackout of HF due to increased absorption at -60 km. These are short lived (up to an hour) but frequently the suddenness causes the operator to look for trouble in his equipment. †¢ A magnetic storm decreases the frequencies capable of being reflected at auroral latitudes, produces absorption, and creates irregularities at F layer heights which cause fading. Absorption is the problem most difficult to deal with in modern systems. †¢ The worst problem for reliability is that of polar cap absorption (PCA) where very high energy protons produce very high level absorption events predominantly over the polar cap. Overhead (without the problem of slant range increases) absorption has been recorded up to 10-20 dB at 30 MHz. In this case the increase of power to overcome the absorption would be enormous. PCAs are rare but their effects can last for several days. This essentially reduces the reliability of HF with the only solution path diversity with the reflecting points chosen outside the polar cap. DEALING WITH PROPAGATION †¢ Path diversity, rerouting of communications to seek the least troubled path has been tried. Multiple frequencies and multiple paths has lead to improvements from 37% reliability (four frequencies-short path) to 62% reliability in a disturbed ionosphere at high latitudes (no error correction or coding). †¢ Dynamic models of solar-terrestrial relationships. In at least two groups real time data from solar, interplanetary, and terrestrial measurements are fed into an elaborate program to forecast effects at high latitudes. These are at beginning stages but they promise much more than the simplistic means of forecasting magnetic storms now in use. HAARP The High Frequency Active Auroral Research Program is an ionospheric research program jointly funded by the US Air Force, the US Navy, the University of Alaska and the Defense Advanced Research Projects Agency (DARPA). Its purpose is to analyze the ionosphere and investigate the potential for developing ionospheric enhancement technology for radio communications and surveillance purposes (such as missile detection). The mos t prominent instrument at the HAARP Station is the Ionospheric Research Instrument (IRI), a high power radio frequency transmitter facility operating in the high frequency band. The HAARP project aims to direct a 3. 6 MW signal, in the 2. 8–10 MHz region of the HF [High Frequency] band, into the ionosphere. The signal may be pulsed or continuous. Then, effects of the transmission and any recovery period can be examined using associated instrumentation, including VHF and UHF radars, HF receivers, and optical cameras. According to the HAARP team, this will advance the study of basic natural processes that occur in the ionosphere under the natural but much stronger influence of solar interaction, as well as how the natural ionosphere affects radio signals. This will enable scientists to develop techniques to mitigate these effects in order to improve the reliability and/or performance of communication and navigation systems, which would have a wide range of applications in both the civilian and military sectors, such as an increased worldwide HF communications, accuracy of GPS navigation, and advancements in underwater and underground research and applications. This may lead to improved methods for submarine communication and the ability to remotely sense the mineral content of the terrestrial subsurface, among other things. HAARP is the subject of numerous conspiracy theories, with individuals ascribing various hidden motives and capabilities to the project. Journalist Skeptic computer scientist David Naiditch called HAARP a magnet for conspiracy theorists, saying the project has been blamed for triggering catastrophes such as floods, droughts, hurricanes, thunderstorms, and devastating earthquakes in Pakistan and the Philippines aimed to shake up terrorists. HAARP has been blamed for diverse events including major power outages, the downing of TWA Flight 800, Gulf War syndrome, and chronic fatigue syndrome. Conspiracy theorists have also suggested links between HAARP and the work of Nikola Tesla (particularly potential combinations of HAARP energy with Teslas work on pneumatic small-scale earthquake generation) and physicist Bernard Eastlund. According to Naiditch, HAARP is an attractive target for conspiracy theorists because its purpose seems deeply mysterious to the scientifically uninformed. Conspiracy theorists have linked HAARP to numerous earthquakes. An opinion piece on a Venezuelan state-run television channels website named HAARP as a cause of the 2010 Haiti earthquake CHAPTER VIII NEW SYSTEMS Several systems which use some of the advanced techniques are operational. Among these are the following: RACE (Radio Telephone with Automatic Channel Evaluation). It was developed to improve the quality of telephone services provided by HF radio to remote areas. Naval HF systems aim towards frequency agility on shipboard platforms where collocation interference is a dominant concern. The UK ICS-3 stresses the radical lowering of all self generated components of the noise floor. Primarily ICS-3 enhances groundwave and skywave transmissions through rapid propagation selection and data handling. SELCAL, scanning and channel evaluation, are now part of operating systems with link quality, selective paths and frequencies, and general channel evaluation available. SELCAL HF networks using scanning are being automated. SNOTEL meteor burst system is run by the U. S. Department of Agriculture to relay snow cover data from over 500 remote sites in the West. There are now vendors and equipment specifically for single-frequency meteor burst networks. The impact of SNOTEL is the economy of a simple data terminal that uses many propagation modes in the relatively unused HF/VHF spectrum. A digital sounder has been applied to network frequency management. The unit, developed at the University of Lowell, allows for frequency agility, numerical processing, system clocks, etc. Equipment development is moving along at a rapid pace using off-the-shelf items such as keyboards, modems, and other digital equipment to meet demands of the new modern HFcommunications. HIGH FREQUENCY INTERNET PROTOCOL (HFIP) It is usually associated with Automatic Link Establishment and HF radio data communications. HFIP provides protocol layers enabling internet file transfer, chat, web, or email. HFIP commonly uses ionosphere propagation of radio waves to form a wide area network that can span thousands of kilometers. HF transceivers in HFIP service typically run 20 to 150 Watts for portable or mobile units, up to approximately 2000 Watts transmitter output for high power base stations with HFIP servers. STANAG 5066 is a common HFIP standard. STANAG 5066. STANAG 5066 Profile for High Frequency (HF) Radio Data Communication is a NATO specification to enable applications to communicate efficiently over HF Radio. STANAG 5066 provides peer protocols that operate above an HF Modem and below the application level. STANAG 5066 includes the (mandatory) SIS (Subnet Interface Service) protocol that enables an application to connect to an HF Modem through a STANAG 5066 server over TCP/IP. This enables a clean separation between application and modem. [pic] The diagram above shows a configuration of three sites communicating by HF Radio, using STANAG 5066 to provide end to end communication between a set of applications. The site shown in detail illustrates how STANAG 5066 fits with applications and hardware. It comprises: †¢ An HF Radio, which is an analogue device. An HF Modem, which converts from analogue to digital. †¢ Encryption (optional). Data Encryption will generally be used with HF Radio, and this will be achieved by an encryption unit (COMSEC) that sits between the HF Modem and STANAG 5066 Server. †¢ A STANAG 5066 server. There will be one STANAG 5066 server associated with the modem. The STANAG 5066 Servers communicate with each other over the HF Modem, using protocols spe cified by STANAG 5066. †¢ One or more data applications communicating with the STANAG 5066 server using the SIS protocol. CHAPTER IX HF RADIO NETWORK CENTRIC WARFARE NETWORK CENTRIC WARFARE Network Centric Warfare, also commonly referred as Network Enhanced Capability, is widely documented and described. Key features include: †¢ Everything is connected, to enable all players to communicate and share information. †¢ A wide mix of technologies and components are involved. †¢ High speed datalinks are utilized where possible. †¢ Many applications are used, from core traditional components such as formal messaging and situational awareness, to new applications such as Video Teleconferencing, Voice over IP, Instant Messaging and Presence. IP (Internet Protocol) is used everywhere. IP as the single network technology is a central technical approach. THE ROLE OF HF RADIO IN NCW In terms of planning an overall architecture the technology constraints lead to several possible views as to how HF Radio fits into the overall communications picture: †¢ A legacy component that will be replaced by newer technologies. †¢ A component f or use in special and selected situations. †¢ A component that will be widely used. †¢ A strategic backup communication mechanism, in the event of satellite failure or destruction. If options 2, 3 and/or 4 are chosen, it is critical that HF Radio is well integrated into the Network Centric Warfare architecture, and that effective application functionality is provided to support a full set of mission critical applications operating over HF Radio. KEY APPLICATIONS OVER HF RADIO A goal of Network Centric Warfare is to maximize information sharing. While not all applications are suitable for HF Radio, a number of applications are. This section sets out a list of applications that may be mission critical, are suitable for HF Radio, and could reasonably co-exist and share an HF link: †¢ Voice. Situational awareness. Situational awareness is a key application for tactical military deployments. †¢ Formal Messaging. Military formal messaging. †¢ Internet Mail. Internet mail over HF is defined as a part of STANAG 5066, using the HMTP (HF Message Transfer Protocol). †¢ Instant Messaging and Presence. XMPP. Presence status reporting and Instant Messagin g can be useful applications for tactical deployments. †¢ Directory. Replication of directory data over HF is important to support messaging applications (address book and security) and configuration for other applications. Web. Limited Web browsing may be useful in some situations in support of mission critical operation. This is quite viable over faster HF links. This is not intended as an exhaustive list, but to give a sense of what could be sensibly achieved over an HF link. HIGH FREQUENCY GLOBAL COMMUNICATIONS SYSTEM (HFGCS) The USAF High Frequency Global Communications System is a worldwide network of 15 high-power HF stations providing command and control communications between ground agencies and US military aircraft and ships. Allied military and other aircraft are also provided support. IAW agreements and international protocols as appropriate. The HFGCS is not dedicated to any service or command, but supports all DoD authorized users on a traffic precedence/priority basis. General services provided by the HFGCS are: †¢ General Phone Patch and Message Relay Services †¢ Automatic Link Establishment (ALE) †¢ HF Data Support †¢ Command and Control Mission Following †¢ Emergency Assistance †¢ Broadcasts †¢ HF Direction Finding Assistance †¢ ATC Support †¢ E-Mail connectivity CHAPTER X CONCLUSION In systems development, Real Time Channel Evaluation is made feasible by both equipment and conceptual advances. The conceptual advances include coding and error correction techniques for security and in order to minimize propagation and interference problems. The availability of digital equipment allows RTCE to select a frequency for a particular path, propagation mode, and modulation selection. Propagation advances include better statistical models as well as advances in short term forecasting methods responsive to changes in solar-geophysical parameters. Forerunners of adaptive HF systems are operational in meteor scatter systems used for data collection as well as other operations. The advances both in equipment and in conceptual system development have been many. HF will continue to be a used portion of the spectrum. Various diversity systems ranging from time to space diversity should be made available to the system operator. Geographical diversity is one of the least used but most important methods of handling problems. New approaches include frequency band extension to higher frequencies in order to use meteor burst transmissions above 30 MHz. BIBLIOGRAPHY 1. Introduction to HF Radio Propagation by Australian Government, IPS Radio and Space service. 2. HF Communications, A System Approach by Nicholas Maslin 1. High Frequency Active Auroral Research Program Wikipedia 2. High Frequency Global Communications System – Wikipedia 3. High Frequency Internet Protocol – Wikipedia 4. HF Radio Network Centric Warfare, research paper published in 09 April 2008, www. isode. com. 5. STANAG 5066: The Standard for Data Applications over HF Radio, www. isode. com. 6. Introduction to HF Radio Propagation by Australian Government, IPS Radio and Space service. 7. Current Trends in Tactical Naval Communications by Stephen Metzger director of sales naval communications at Rhodes and Schwarz. . General Concepts of Modern HF Communications by Jules Aarons Boston University. 9. Modern HF Mission Planning Combining Propagation Modeling AND Real-Time Environment Monitoring by D. Brant, G. K. Lott, S. E. Paluszek, BE. Skimmons Applied Research Laboratories, The University of Texas at Austin, USA Naval Postgraduate School. 10. Modern Aircraft H F Communications into the 21 Century by N C Davies, M J Maundrell, P C Arthur, P S Cannon, R C Bagwell, J Cox, UK Defence Evaluation and Research Agency. 11.

Vital Pieces of Research Paper Topics Sir Phillip Sidney

Vital Pieces of Research Paper Topics Sir Phillip Sidney To begin with, there was not any curtain like there's today. He was knighted the identical calendar year. Nonetheless, in modern theatres, orchestra seats are definitely the most expensive and the very best seats. She stated that she'd love to see Australia become a republic, with an acceptable time being when there's a change in monarch. He did not obtain another big official appointment until eight decades later. Yes, we're speaking about William Shakespeare. Spencer made a new poetic form whilst developing this poem. He wishes to observe how best Love and Virtue can do the job together. Sir Philip Sidney is among the most famed poets of the Renaissance period. Sidney and Lady Penelope was betrothed while the latter was a kid. The History of Research Paper Topics Sir Phillip Sidney Refuted The talent of poets comes from their capacity to make something new by employing a pre-conceived idea called the fore-conc eit. All facets of the literary techniques within this sonnet suggest some sort of internal conflict between the speaker and his interlocutor. Regardless of the orientation of all of the Renaissance authors on similar patterns and adhering to the exact principles, their works are characterized by a great deal of peculiarities and differences. Nevertheless in my opinion there's a flaw of the structuralist concept that was stated above. To put it differently, there's no sort of poetry that doesn't repay closer inspection, because these examples have tried to highlight. This isn't an instance of the work generated by our essay writing service. Other sonnets explain that because everyone can use artful ways to make himself or herself more attractive, nobody is actually beautiful anymore. Due to her sensibilities, she views marriage for a surrender of her freedom and for that reason resists love. This is done in order to demonstrate reverence to it and its ability to sooth our w orries. It will provide them idea that this type of life is possible. He raises a query in the last line of this quatrain, if everyone can cope with the confines of love together with the boundaries it seems to put on someone. It's all because they're in love with the bodily attributes of the women. Nature gave the young man a gorgeous face, but it's the youthful man's responsibility to be certain that his soul is worthy of such a visage. This suggests that desire is never a great thing and is flawed, because it can't even attain the target of ruining its victim. There's nothing analytic regarding the rationality of justice and benevolence. Gosson is afraid people will prioritize tangible development than the standard awareness of morality. It can present factual data in a manner which people can understand. This course provides a roadmap. In reality, there's no conflict in the slightest. Additionally, it concentrated on secular difficulties. There's no evidence he ever spoke in the House. This argument shows Sidney's reasoning that Astrophil's reason isn't functioning in its responsible field, but instead, being nosy in another domain, and should be put back to where it needs to be. Certain qualities common to the sonnet for a form needs to be noted. Plato is among the most notable examples of a fantastic philosopher and poet. But Shakespeare chose to joke about such metaphors and explain that a woman really doesn't have those qualities. Yet there are numerous different types too, like the modern, and twentieth century sonnets. Bearing this in mind, here's a list of words which shouldn't be forgotten by poets and writers that are likewise nature lovers. This entry comprises critical essays focusing on Sidney's function in the Age of Spenser. Literature wasn't evaluated thro ugh criteria. This can be viewed as a forerunner of the movement to the use of the vernacular in English poetry. English Renaissance isn't an isolated phenomenon. Don't hesitate to combine distinctive topics or change them in order to create your own topics for King Lear.

Opinion Essay Topics For 3rd Grade

Opinion Essay Topics For 3rd GradeOpinion essay topics for 3rd grade should be carefully considered. Essays should be written with the best interests of the child in mind, but not so that it contradicts the principals of the school curriculum or if it is used to try and gain a reputation.The fact is that opinion essay topics for 3rd grade can be tricky. If the topic is at odds with what the teachers believe or the principals say, they can come across as inappropriate. Let's take a look at a few situations that might present themselves.One is writing an opinion essay topics for 3rd grade on whether it is okay to drive a vehicle if a child has a medical condition like sleep apnea. This would conflict with how drivers are medically evaluated by their doctor. Sleep apnea is not the greatest thing to be driving around while you're going through a very serious sleep disorder.Another issue here could be how to write an opinion essay topics for 3rd grade on whether it is appropriate to play a game where a child can become the teacher and test the students on the amount of knowledge they have acquired. We all know that many children learn less than their peers. A game like this might make it appear as though the teacher is only testing the student's ability to memorize facts and figures, when it could very well be that the student has not acquired any particular knowledge.One last example of an opinion essay topics for 3rd grade would be writing an opinion essay topics for 3rd grade on whether or not sports may be damaging to a child's development. Children spend most of their time playing sports either through participation or recreation. Many child psychologists agree that even moderate contact sports like football or hockey have detrimental effects on developing minds.Another form of this topic would be the idea of writing an opinion essay topics for 3rd grade on whether a mother's breast feeding is a problem. This issue is highly debatable. The way that mothers brea st feed their babies will be discussed here, but let's just say that the issue does get to the doorstep of some of the most powerful people in the world.So when deciding the opinion essay topics for 3rd grade, remember that all of these issues should be carefully studied. Perhaps a parent could contact the education staff or the principal to see if there is any evidence to back up their concerns. It is all part of being a good parent.As you can see, there are many different opinions on opinion essay topics for 3rd grade. Make sure that you consider your child's needs and be sensitive to the issues that come up.

Writing an Effective College Argumentative Essay

Writing an Effective College Argumentative EssayYou've probably heard a lot about a college argumentative essay, and you're wondering how to write one. Well, if you want to impress your college admissions officers and score a higher grade on your essay, you need to know a few things before you start writing that essay.The first thing you need to do when you're writing a college argumentative essay is to understand that you are writing a kind of essay that college students are expected to read, even if they don't necessarily understand it. Some college students find it hard to read and understand essay topics, so you want to make sure that the information you give them is fairly simple to understand. However, if they have trouble understanding what you're saying, you can take out parts of the explanation and clarify the information at the end of the essay.A second thing to remember when you're writing a college argumentative essay is that you need to make sure you use plenty of exampl es and illustrations to make the points you're trying to make. It's best to use some images and pictures as well, but you don't need to include them all of the time.When you're writing a college argumentative essay, you also need to be careful to avoid stereotyping people and situations. For example, if you're writing about the plight of working mothers in today's society, you don't want to sound like you're condemning all working mothers as lazy or unappreciative.Also, when you're writing a college argumentative essay, you should avoid using negative words or phrases that could lead to negative responses from your readers. College admissions officers generally prefer essays that are factual and straightforward; therefore, you need to make sure you use positive words and statements to make the case for your arguments.Another thing to keep in mind when you're writing a college argumentative essay is that you shouldn't do the whole 'scare' tactic too much. One word of warning: if you scare your reader with a specific situation, you will probably not get them to agree with your argument, and your entire argument may be invalidated.Last, when you're writing a college argumentative essay, you need to be sure to use well-developed arguments and good writing skills. Remember that if you want your college essay to be well-received, it must be well-written and well-organized.As you can see, there are a few things to keep in mind when you're writing a college argumentative essay. Keep them in mind when you start thinking about your topic, and you should be able to write an effective essay that makes the admissions officer who reads it thinks positively about you.

David Henley and David English - Two Great Teachers

David Henley and David English - Two Great TeachersThere are many debates in the World of Debate, however few hold the status of Debate Masters as that held by David Henri English. His mastery in what may be termed Debate Critique has made him the world leader in his field and has placed him at the pinnacle of international debate. English is an accomplished writer and his ideas on the debate game have been passed from one generation to another with longevity. If you are interested in learning about the different arguments used in Debate, you should take a look at the following Debate Masters and determine if English is the right one for you.Henri English, LPDDA, is considered the Father of Modern Debate. He is well known for his amazing speeches that were written by him. These speeches are often characterized as being well paced and are even used as testaments in the past. His style was so unique and his ideas and opinions so well thought out that even other professors of debate stu dies recognized him as the father of debate. English's accomplishments in the field of debate have not been limited to this, but have gone on to inspire thousands of current and future coaches who are making their mark in the world of debate.David Henri English, LPDDA, is considered the first Pro BBL judge. He is responsible for the creation of the bbl is not allowed after the finals in the amateur league for the Professional National Basketball Association in America. His style has won him numerous awards and honors, which is why many consider him to be the greatest Pro BBL judge ever.English's teaching methods are known for their consistency. These methods are not the same for all of his students, but they share the same philosophy of excellence that this man holds. If you are interested in learning about English's method of teaching, you should take a look at the following two Debate Masters.David Henney, LPDDA, is considered by many to be the best Debate Master that ever lived. In fact, the Honorable Martial Arts Champion and BBL Winner recently announced that he would be retired from the game. This is an amazing accomplishment considering that he has been involved in the game since it was born and continues to teach at his institution. His methods have garnered national recognition and awards, which is why many consider him the greatest ever to do it.Henry Davison, LPDDA, is considered the greatest English teacher in the world. The idea of English being able to do all this and continue teaching at his level is an impressive feat, which has made him a lot of money and gave him a lot of accolades over the years. His methods are unmatched, and his ideas on the debate game remain with us today.Regardless of who you choose as your Debate Master, you will be able to learn a lot more from the two of them than you could from most instructors. If you are interested in learning more about this career, take a look at the following two great teachers, and determine i f they are the right one for you.

Positive Behavioral Supports

Introduction Education 50 years ago was not what it is like today. Schools today are confronted with a vast amount of issues. Within those issues are student achievement, school violence, lack of parental support, and behavioral concerns within the school community and in the classrooms.Advertising We will write a custom thesis sample on Positive Behavioral Supports specifically for you for only $16.05 $11/page Learn More Bowen (n.d.) found that various studies have shown that students who act up in school express a variety of reasons for doing so. Some think that teachers don’t care about them and others don’t want to be in school at all while many don’t consider goal setting and success in school important anymore. Despite these hurdles, students agree that discipline is needed in schools. One high school student stated: â€Å"If there were no discipline, the school would not be distinguished from the street.† Bennett (1999) states that most surveys show that Americans complain that too many schools are disorderly, undisciplined places. How much are students really learning when the main focus in our schools today is student behavior and discipline? Many different programs have been presented to schools in efforts to help alleviate some of the discipline problems found in schools and in the classrooms. PBIS (2009) states that â€Å"a major focus for current policy and systems change efforts in education is the extent to which states are investing in practices and procedures that are supported by rigorous research evidence.† Positive Behavior Support (PBS) is a research-based theory that supports the idea that a student’s behavior can be changed if a full understanding of the child is gained. Through positive interventions students are able to reduce the negative behavior and increase the more desirable one. This literature review will examine the literature related to Positive Behavior Su pport, its foundations and the advantages and disadvantages of implementing PBS.Advertising Looking for thesis on education? Let's see if we can help you! Get your first paper with 15% OFF Learn More Origins of Positive Behavior Support Positive Behavior Support is relatively new to the scene of school reform because it was mainly known as behavior modification for special education students who displayed difficult behaviors. The origins of PBS can be traced back to the theory of Applied Behavior Analysis, an expansion of the operant conditioning theory first developed by B.F. Skinner, the American psychologist. A survey performed by Frey (2006) of four hundred teachers revealed that teachers felt that operant conditioning was effective at managing behavior of both groups and individual students. Positive Behavior Support: A Three Tier Continuum It is important to express that like academic forms of instruction, students also require different levels of behavioral inte rventions and different types of support in order to do well in school. Positive Behavior Support focuses on three key levels within a continuum, according to Nelson, Hurley, Synhorst, Epstein, Stage Buckley (2009) the first tier entails â€Å"universal interventions that are expected to prevent the onset of problem behavior in a majority of children altogether and to sustain improvements in child outcomes by the selected and indicated interventions.† This level is known as universal because it delineates school-wide behavioral expectations for all students along with consistent consequences for unwanted behaviors. Level two also known as tier two is mainly for students who still continue to demonstrate problem behavior after tier one was implemented. Tier two on the continuum focuses more on small group interventions. A study done by McIntosh, Campbell, Carter, Dickey, (2009) examined the effectiveness and differential effects of a tier two daily behavior intervention. Thi s study was conducted over an eight week period and the samples were 36 students. The findings confirmed that the amount of office referrals lessened after small group and targeted interventions were established.Advertising We will write a custom thesis sample on Positive Behavioral Supports specifically for you for only $16.05 $11/page Learn More The final tier consists of a more personalized or individualized intervention. Lewis, Colvin, Sugai (2000) state that â€Å"approximately 5% to 7% of the students will require highly individualized behavior support.† Challenges Faced While Implementing Positive Behavior Supports Weinberger (2009) conducted a study using a mixed methodology that identified the strengths and limitations of the implementation of Positive Behavior Supports. Via surveys, case studies focus groups, and behavioral data of students. The study revealed that although student behavior did not improve, the implementation of PBS wa s successful because it was able to identify specific information needed to provide individual interventions to students. A study carried out by Guthals (2009) expressed that there is no evidence of direct correlation between student achievement and the implementation of PBS. Data pertaining to the study was collected through optional surveys completed by school principals concerned about the immense number of office referrals and discipline problems in the classrooms taking a toll on student learning. While direct correlation between what was intended to be tested, the relationship between student achievement and the implementation of PBS, the surveys conveyed that administrative stress level had decreased after the implementation of PBS. Today’s schools must address the behavioral needs of all students at a number of different levels (Mogan-D’Atrio, et al 1996). First, there must be schoolwide efforts that teach positive communication and social interaction skills, a nd develop positive school routines designed to prevent behavioral issues throughout the school day (Fishbaugh Furshong, 1998; Scott, 2001; Taylor-Greene et al., 1997). Second, in conjunction with schoolwide efforts, classroom norms and routines can be established by educators, in collaboration with their students, to create a sense of caring and community in the classroom.Advertising Looking for thesis on education? Let's see if we can help you! Get your first paper with 15% OFF Learn More Third, behavioral issues must be addressed at the individual student level for students who have more intense, ongoing behavioral challenges. Addressing issues of school safety at the individual student level takes place through the creation of positive behavior support plans (Sailor et al 2007). Advantages of Implementing Positive Behavior Supports In light of increasing frequency and intensity of disruptive behaviors in schools nationwide (Martin, Lloyd, Kauffman and Coyne, 1995), policymakers and school practitioners are increasingly considering the benefits of teaching and supporting pro-social behaviors to decrease disruptive behaviors and increase academic success. Urban schools, in particular, face challenges with limited resources and large numbers of students, many of who are living in poverty or violence-prone environments (Netzel and Eber, 2003). Traditional, and more reactionary, school discipline procedures (e.g., those that rely on punishment and exclusion) are general ly ineffective in either reducing challenging behaviors or increasing desired behavior (Mogan-D’Atrio, Northrup, LaFleur and Spera, 1996). One promising alternative, Positive Behavioral Interventions and Supports (PBIS), is a school-wide approach that promotes social competence through a system of behavioral support wherein expected behaviors are defined, taught, and rewarded. Schools implementing PBIS establish a continuum of proactive, positive discipline procedures for all students across all settings. Universal school-wide strategies are intended to facilitate success for 85-95 percent of the students (Mogan-D’Atrio, et al 1996). The National Conference of the Hamilton Fish Institute On School And Community Violence while targeted small group or individual interventions are designed for the types of students for whom universal strategies have not been successful (5-15 percent (Mogan-D’Atrio, et al 1996). Last, for the one to seven percent of students who hav e chronic and intensive needs across multiple settings, a wrap-around approach is implemented (Eber, Sugai, Smith, and Scott, 2002).Several studies have demonstrated positive effects of PBIS, with some recent research showing success in urban settings. For example, Netzel and Eber (2003) report a 22 percent reduction in suspensions after one year of universal level implementation (e.g., teaching school-wide rules and recognizing and acknowledging appropriate student behavior) in an urban elementary school. Further, Netzel and Eber report a number of encouraging outcomes during the 1st full year of school-wide PBS implementation, including a 20 percent decrease in office discipline referrals, 23 percent decrease in â€Å"time-outs,† and 57 percent decrease in short-term suspensions. Few studies, however, have demonstrated the impact of PBIS in urban settings across a number of different variables and over a number of years. Managing Disruptive Behaviors through Positive Behavi or Supports Misbehavior in K-12 schools hurts every participant. Te misbehaving student is often sequentially moved into more academically impoverished environments; other students are distracted, and teachers are forced to become disciplinarians (Sandomierski, et al 2007). Furthermore, a costly administrative infrastructure; including the very valuable and very limited time of the school principal; is monopolized to deal with discipline problems. A third grader acting up in class does not act up because s/he was born a â€Å"bad kid† (Sailor et al 2007). Most likely, s/he has not yet learned the social skills appropriate to that setting, or there is something in the classroom setting, or a learning disability, or a family issue that interferes with his or her ability to behave properly (Sandomierski, et al 2007). Unfortunately, school discipline systems focus more on punishing kids than on giving them the skills, training, and incentives to behave properly. Behavioral remedi ation, where it exists, typically takes the form of a fifteen-minute weekly visit to a school counselor. Just as if the student was trying to learn math by scheduling a fifteen-minute weekly chat with a math teacher, the system tends to fail the students (Sailor et al 2007). Research points to the benefits of systems that teach and support positive behavior, rather than simply punishing negative behavior. By adopting a positive behavior support (PBS) system, individual schools, districts, and states have dramatically reduced office referrals and suspensions, increased on-task academic time, and made students, teachers, and parents more satisfied with the school. Positive Behavior Support systems have been implemented by a large number of school districts and states, including North Carolina. Vermont is currently implementing PBS. Discipline referrals and suspensions often drop 40-60% over the first two years that the program is implemented (Sandomierski, et al 2007). Principals may save six full workdays worth often-minute visits over the course of a year. In schools with severe behavior problems, teacher satisfaction under PBS may increase by 60%, leading to a more experienced, stable staff. When a third grader misbehaves, it represents not a personal failure, but a failure of the systems around him to equip him for the setting he is in. We can stop this failure by shifting the focus to preventing misbehavior, rather than just punishing it. Providing serious behavioral support to students pays off by reducing distraction and improving academic outcomes, reducing costly referrals to special education, and letting teachers and principals do their job rather than spend all their time on discipline (Sailor et al 2007). Rather than being transferred into special education or punished to the point of dropping out, students with behavior problems are put on a path to social and academic success. Positive behavior support programs in a school may employ a three-tier model. The first tier is a low-intensity, school-wide misbehavior prevention program involving things like certificates of recognition for such pro-social behaviors as picking trash and putting it in the trash can. These programs are targeted to build the skills of the majority of students (80-85%) who have 0-1 office referrals. The second tier of students (10-15% with 2-5 office referrals) typically have significant behavior problems and require intervention, such as group sessions with school psychologists to learn appropriate behaviors, just as they would learn any other skill set in a classroom setting. Te goal of these sessions is to help them emulate their better-behaved classmates, rather than imitating those with more severe behavioral problems. Te third tier (typically 5% with 6+ office referrals) suffers from severe behavioral problems, requiring individualized interventions. Conclusion Results indicate that implementation of universal Positive Behavior Support (e.g., teac hing behavioral expectations, rewarding positive behaviors) in Year 1 and beginning targeted level intervention (targeting small groups of students with two to five behavior referrals for small group interventions) in Year 2 leads to positive changes in one of the two schools examined. Specifically, Addison School demonstrated overall decreases in ODRs, as well as decreases in the most frequent problem behavior and locations over the first 1.5 years of implementation (Sandomierski, et al 2007). These latter two are particularly noteworthy, as they exemplify the successful use of data to target problematic behaviors and contexts. Classroom referrals were specifically targeted in Year 2 through the addition of classroom management training for teachers. Problematic behaviors on the bus were specifically targeted that same year through the addition of bi-monthly bus driver training breakfasts. Teacher ratings on our surveys showed some positive changes across the two years as well, wit h teachers generally rating the existence of negative behaviors lower in Year 2, while pro-social behaviors were rated more highly, although it should be noted that only one of these differences reached statistical significance. Findings further suggest the need for full implementation of the PBS model. These schools are relatively strong in universal level implementation, but are still in the beginning stages of implementation of the targeted level, and have not yet begun intensive-level intervention. These latter two levels are important in decreasing referrals from the most chronic misbehavers, and intervention here would likely have a much greater impact on overall referrals as well as the schools’ â€Å"triangle† profiles and teacher perceptions of both student behavior and effectiveness of the intervention. This finding is consistent with teacher concerns as noted in focus groups and in survey results. Furthermore, given time needed for full implementation of the model, as well as systems-change research indicating that three to five years are necessary to implement full school change (Sandomierskiet al 2007), an evaluation of the effectiveness of such school-wide interventions should additionally allow for a minimum of three years of data. References Eber, L. Sugai, G. Smith, C. and Scott, T. M. (2002). Wraparound And Positive Behavioral Interventions And Supports In The Schools. Journal of Emotional and Behavioral Disorders, 10, 136-173. Frey, S. (2006). Teachers and Operant Conditioning. Retrieved from ERIC database. Guthals, J. The Relationship Between Positive Behavior Supports, Student Achievement, Severe Problem Behavior, And Administrative Stress. Ed.D. dissertation, University of Montana, United States — Montana. Lewis, T., Colvin, G., Sugai, G. (2000). The Effects of Pre-Correction and Active Supervision on the Recess Behavior of Elementary Students. Education Treatment of Children, 23(2), 109. Retrieved from Academic Sea rch Premier database. McIntosh, K., Campbell, A., Carter, D., Dickey, C. (2009). Differential Effects of a Tier Two Behavior Intervention Based on Function of Problem Behavior. Journal of Positive Behavior Interventions, 11(2), 82-93. OmniFile Full Text Mega database. Martin, K. F., Lloyd, J. W., Kauffman, J. M., and Coyne, M. (1995). Teachers’ Perceptions Of Educational Placement Decisions For Pupils With Emotional Or Behavioral Disorders. Behavioral Disorders, 20, 106-117. Mogan-D’Atrio, C., Northrup, J., LaFleur, L., and Spera, S. (1996). Toward Prescriptive Alternatives To Suspensions: A Preliminary Evaluation. Behavioral Disorders, 21, 190-200. Nelson, J., Hurley, K., Synhorst, L., Epstein, M., Stage, S., Buckley, J. (2009). The Child Outcomes of a Behavior Model. Exceptional Children, 76(1), 7-30. Retrieved from Academic Search Premier database. Netzel, D. M. and Eber, L. (2003). Shifting From Reactive To Proactive Discipline In An Urban School District: A Chan ge Of Focus Through PBIS Implementation. Journal of Positive Behavior Interventions, 5, 71-79. PBIS. March 2009. Is School-Wide Positive Behavior Support An Evidence-Based Practice? (2009). Web. Ps@?under, M. (2005). How Effective Is School Discipline in Preparing Students to Become Responsible Citizens? Slovenian Teachers’ and Students’ Views. Teaching and Teacher Education: An International Journal of Research and Studies, 21(3), 273-286. Retrieved from ERIC database. Sailor, W., Stowe, M. J., Turnbull, R., III, Kleinhammer-Tramill, P. J. (2007). A Case For Adding A Social-Behavioral Standard To Standards-Based Education With School-Wide Positive Behavior Support As Its Basis. Remedial and Special Education, 28, 366–376. Sandomierski, T., Kincaid, D., Algozzine, B. (2007). Response To Intervention And Positive Behavior Support: Brothers From Different Mothers Or Sisters With Different Misters? PBIS Newsletter 4(2). This thesis on Positive Behavioral Supports was written and submitted by user Tinley Forbes to help you with your own studies. You are free to use it for research and reference purposes in order to write your own paper; however, you must cite it accordingly. You can donate your paper here.

Shouldice Hospital Case Report Essays

Shouldice Hospital Case Report Essays Shouldice Hospital Case Report Essay Shouldice Hospital Case Report Essay Subject: Problems and Plans Operational Assessment of the Shouldice Hospital Thank you for the opportunity to consult on your Shouldice Hospital operational assessment. I understand that you have implemented a well developed focus strategy (market focus and internal focus) successfully and Shouldice achieves outstanding results by maximizing the difference between perceived quality and value to the patient on one hand and the cost of supplying services on the other. The nurses and doctors treat their patients with care and understanding and treat them more like family members. This has led to the high level of praise for this hospital and its treatment. The rising number of satisfied patients and word of mouth referral has led to demand for the facilities services which outstrip the facility’s current capacity. I understand that you are looking for guidance on specific actions in order to increase the hospital’s capacity while at the same time maintaining control over the quality of the service delivered, and the hospital management. I have identified the problems and offered a list of alternate courses of action. Problem Definition: The problem is that Shouldice is facing a paradox of change. Shouldice is operating at its â€Å"best operating level† for a service company with limited flexibility in its facility, a specialized work force but are failing to meet all the demand for its chosen market niche. Adding additional capacity to meet the unmet market need may upset the existing work force and lower service quality. Failing to meet the market demand may invite competition that could eventually cause Shouldice to lose market share and end up with excess capacity. Problem Justification: It is assumed that they are operating at the â€Å"best operating level† because the way the case describes how efficiently the hospital is ran and how the patients appear to be pleased with their treatment. Capacity is nearly 100% full if they do 30 operations a day and the patients stay 3-4 days. This would fill up 89 beds for a 5 day work week. They also have 15% (14 hostel rooms) additional capacity for peak times. This also works out to be about 70% capacity of their full time potential of 7 days. 70% of maximum capacity is the best operating point. To increase it rate of service utilization will decrease the service quality. For capacity analysis, refer to Appendix-B. To increase their output and maintain their quality they would need to increase the size of the hospital. This involves large capital investments and considerable time. Construction would also cause a disruption to the quality and country club atmosphere of the hospital. Due to shift restrictions the current operating rooms are completely un-utilized for 2 days of the week as well as 15. 5 hours of each weekday. Kitchen and common area are designed to accommodate one hundred patients and it is important that these facilities be kept up to ensure patients still receive the high level of satisfaction with the experience at Shouldice. The staff also has limited flexibility. Surgeons and surgeons’ assistants are specialized fields that have limited desire to be cross trained. It is assumed that the staff is happy with the existing work schedule and do not want a change. Increasing the days worked would cause more aggressive scheduling of the operating rooms and may make it hard to maintain the same kind of working relationships and attitudes. Alternative Courses of Action: Alternative courses of action are based on the assumption that the reason for their desired expansion is to meet an unmet market demand. i) They could add an additional day by operating on Saturday. ii) They could do nothing different and continue to do as they are currently doing. iii) They can add a new floor (i. e. 45 i. e. 50% more hospital beds). iv) They can meet the unmet market demand with external capacity (establish a new facility). v) They can utilize the current facilities during some of its present idle time. Evaluate alternatives and make decisions: i) Adding an additional operating day on Saturday is a valid consideration. It would utilize ideal hospital capacity. It could increase the number of patients served by 9% or 800 patient a year. Would this be a sufficient number of patients served to keep competition from entering the same market is unknown. Adding a Saturday is also assumed to have a negative impact on the work force that drive down the quality that gives Shouldice a competitive advantage. It would increase rate of service utilization beyond 70%. This could be offset by hiring addition staff. But one should consider the time it takes the new staff to come up the efficiency curve. For capacity analysis and financial details refer to Appendix-C. ii) Doing nothing is a valid consideration. Their existing system and reputation sets them apart as a market leader and it is assumed to be a profitable setup. If it is working do not try to fix it. We assume that the existing set up is acceptable to management as far as profit and other operating measures. The assumed risk is if they do not do anything then competition will enter the market place and could eventually take patients away from Shouldice. There is insufficient data presented to truly analyze this risk. iii) Increasing the number of bed by 50% would not be advisable unless they added more doctors and surgery rooms because the existing plant capacity and number of doctors could not fill an addition 45 beds. They would be operating the surgery rooms at over capacity. The construction requires large capital investment, time, and would disrupt the country club atmosphere. For capacity analysis and financial details refer to Appendix-D. iv) Meeting the unmet market demand with external demand is a valid consideration. It could be done in several different ways. They could look to other facilities that are similar and team with their doctors to train them in the Shouldice processes and share in the profits. This would help keep the competition out of the market and could be done as a silent partner until the service quality reaches a level that Shouldice would want to associate their name with the other facility. Another option would be to establish a new facility for Hernia. Another option would be to subcontract or franchise the operation. For merits and demerits refer to Appendix-E. v) Relieve the operating room bottleneck by utilizing the current facilities during some of its present idle time. Addition of weekend or evening surgeries will increase throughput without any capital investment. Expand the facility’s kitchen and social area’s to accommodate the increased patient throughput and continue to provide a high quality patient experience for its customers. Recommendations: I would recommend a combination of doing nothing with the existing staff and plant as to maintain the country club atmosphere and gregarious nursing staff that gives it its competitive advantage and meet the unmet market demand with external sources of capacity to keep the competition from entering the market. I would be happy to elaborate on my recommendations in future correspondence. Sincerely, An MBA Student Appendix-A Cost comparison – Shouldice vs. Other Hospitals: Cost Items| Shouldice| Other Hospitals| Remarks| Costs of typical operations| $954*| $2000-4000| * Without general anaesthetic| Transportation(round-trip fares for travel to/from Toronto)| $200-600| $200-600 **| **No data available. Considered the same as Shouldice. | Time Lost from work in Hospital| 04 days| 05 days| | Time lost from work while recovering| 05 days| 10 days| | Value of time lost (ranging from $50 to 500 per day)| $450-4500| $750-7500| | Total before Allowancefor recurrence| $1604-6054| $2950-12100| | Probability of Recurrence| 0. 80%| 10. 00%| | Expected Cost of Recurrence| $13-48| $295-1210| | Total cost to patient, employee and insurer| $1,617-6,102| $3,245-13,310| | Profitability of Shouldice Hospital Clinic: Hospital: Items| Shouldice Hospital| Remarks| Revenues per year(4 days X $111/day x 6,850 patients/year)| $3,041,400| Charges for hospital stay = $111/day. Operations per year = 6,850 (in 1982)| Cost per year| $2,800,000| | | | | Profit per year (A)| $241,400| | Clinic: Items| Shouldice Clinic| Remarks| Revenues per year(($450 + 60 + 75 X 0. 20) X6,850)| $3,596,250| Surgical fee=$450/operation. Fee for the assistant surgeon=$60. Fee for a general anaesthetic =$75. Operations per year=6,850 (in 1982)| Cost per year| $2,000,000| | | | | Profit per year (B)| $1,596,250| | Total (Hospital + Clinic) Profit per year (A+B)| $1,837,650| | Total Depreciated Assets = $5 million Return on Asset = $1,837,650/$5 million = 0. 36753 i. e. 37% Appendix-B Current Capacity Analysis Current Throughput: * 6,850 Operations/50 weeks = average 137 operations/week with a peak of 165/week in September. Capacity Analysis: * Examination Rooms: (6 rooms x 3 hrs (1-4 PM) x 5 days x 60 min/hr) / (20 min / exam) = 270 patients /week = 54 patients/day. * Admitting Procedure: (2 people x 4 hrs (1-5 PM) x 5 days/week x 60 min/hr) / (10min/patient) = 240 patients/week = 48 patients/day. * Nursing Station: (2 stations x 4 hrs (1-5 PM) x 5 days/week x 60min/hr)/ (10 min/patient) =240 patients /week = = 48 patients/day. * Operating Rooms: (5 rooms x 8. 5 hrs/room/day x 5 days/week)/ (1. 1 hrs/patient) = 187 patients /week = 37 patients/day. Average operation time = (82% x 45 min + 18% x 90 min) + 15 min file time = 68. 1 min/operation. * Surgeons: 12 surgeons x 3. 5 operations/day x 5 days = 210 patients/week = 42 patients/day. * Hospital rooms: 89 rooms = 147 patients per week (assuming 3. 5 days average stay, 3 days recovery and Monday – Wednesday admittance, No procedures on Saturday or Sunday only recovery and admittance) – 29 patients/day. 103 rooms (incld. 14 hostel rooms) = 161 patients (assuming 3. 5 days average stay, 3 days recovery and Monday – Wednesday admittance, No procedures on Saturday or Sunday only recovery and admittance and use of 14 â€Å"hostel† rooms for two nights each week) – 32 patients/day. Current: Check-in day| Beds Required| | Monday| Tuesday| Wednesday| Thursday| Friday| Saturday| Sunday| Monday| 30| 30| 30| 0| 0| 0| 0|. Tuesday| 0| 29| 29| 29| 0| 0| 0| Wednesday| 0| 0| 29| 29| 29| 0| 0| Thursday| 0| 0| 0| 29| 29| 29| 0| Friday| 0| 0| 0| 0| 0| 0| 0| Saturday| 0| 0| 0| 0| 0| 0| 0| Sunday| 30| 30| 0| 0| 0| 0| 30| | | | | | | | | Total Number in Hospital| 60| 89| 88| 87| 58| 29| 30| Total number of patients per week| 147| Appendix-C Adding an additional operating day on Saturday Use current 89 beds + 14 hostel rooms. Consider 3. 5 days average stay. Total number of patients per week = 180. Current throughput = 137 operations/week (refer to Appendix-B). Theoretical throughput = 161 patients/week (refer to Appendix-B). So, new throughput = (137/161)*180 = 153 patients/week. Therefore, additional patients per week = 153 – 137 = 16 Additional patients per year = 16*50 = 800 Additional revenue = 800*(450+75*0. 20) = $372,000 Total cost = $124,250 Therefore, Net increase in profit = $372,000 $124,250 = $247,750 for no additional investment. Demerits of this alternate action: * Require to schedule 23-25 operations on Saturday. * Six surgeons and a supervising surgeon have to work on Saturdays. * Additional other personnel (an anesthetic, nurses). * Violates the implied contract that Shouldice has with its surgeons, strong opposition by the senior doctors. * Operating close to the theoretical capacity of the facility. Merits of this alternate action: * No investment is needed. * Can still maintain quality service. Appendix-D Increasing the number of bed by 50% Current number of beds: 89 Add in a new floor (expand the capacity by 50%) at the cost of $2 million: 45 beds Total beds = 89+45 = 134 Total number of patents per week = 210 Current throughput = 137 operations/week (refer to Appendix-B). Theoretical throughput = 161 patients/week (refer to Appendix-B). So, new throughput = (137/161)*210 = 179 patients/week. Therefore, additional patients per week = 179 – 137 = 42 Additional patients per year = 42*50 = 2100 Additional revenue = 2100*(450+75*0. 20) = $ 976,500 Total cost = $176,500 Profit = $ 976,500 $176,500 = $ 800,000 Therefore, Return on investment (ROI) = $800,000/$2,000,000 = 40% Demerits of this alternate action: * Require to schedule doctors to the full capacity of five days per week * Increase work load on admissions, kitchen, laundry, housekeeping and accounting * Further staggering of meal hours for patients (100 seat dining room) * Disruption during construction. * Expensive Merits of this alternate action: * Easy to control and maintain quality * Retain the culture and environment Addition of 45 beds: Check-in day| Bed Required| | Monday| Tuesday| Wednesday| Thursday| Friday| Saturday| Sunday| Monday| 42| 42| 42| 0| 0| 0| 0| Tuesday| 0| 42| 42| 42| 0| 0| 0| Wednesday| 0| 0| 42| 42| 42| 0| 0| Thursday| 0| 0| 0| 42| 42| 42| 0| Friday| 0| 0| 0| 0| 0| 0| 0| Saturday| 0| 0| 0| 0| 0| 0| 0| Sunday| 42| 42| 0| 0| 0| 0| 42| | | | | | | | | Total Number in Hospital| 84| 126| 126| 126| 84| 42| 42| Total number of patients per week| 210| Appendix-E. Meeting the unmet market demand with external demand – Establish a new facility Merits of establishing a new facility: * New location close to current setup, say a major city (New York) in USA * Improve its competitive position and increase its profits * Operate in a less restrictive environment * New Opportunities for existing personnel * Transfer of knowledge and expertise to the new facility. Demerits of establishing a new facility: * Requires a significant investment and time * Difficult to maintain Quality control * Difficult to create the same culture and atmosphere * Potential competition with the existing facility.