Saturday, January 25, 2020

Modulation Systems Used In Satellite Communications Computer Science Essay

Modulation Systems Used In Satellite Communications Computer Science Essay Satellite is the one of the greatest means of communication carrying a large chuck of voice and data stream from one part of the horizon to the other as compared to other medium. In this modern age, communication satellite networks are an indispensable part of the major telecommunication systems. Satellite interconnects the nodes and provides some better advantages in application than the traditional communication systems such as interconnecting large traffic nodes (e.g. telephone exchanges), mobile communication and provision of end to end connections directly to users, television and sound broadcast directly to the public [1]. To provide the optimum quality of services (QoS) different types of design techniques needs to be consider for different purposes like distinct types of modulation and coding (channel and source) techniques are used for specific purpose, link budget calculations, selection of radio frequency (RF) etc. Other dominating factors are: permitted earth station size and complexity, the size and the shape of the service area etc [2]. The objective of this paper is to describe different types of modulations systems using for satellite communications. In this report, first I am trying to give some basic information related to the modulation systems and then bring all possible modulation schemes used in satellite communications. Modulation: In general view, modulation is the process where the characteristics (phase, frequency or amplitude) of the high frequency carrier are varied in accordance with the baseband signal. The baseband signal carries the basic information such as the output of video camera, voice coder or digital television. In practical point of view, it is more convenient to carry the modulation at the intermediate frequency-typically 70MHz [1]. Satellites are usually operate at Gigahertz range of frequency and the modulation signals are up-converted to the transmission frequency and amplified before going on air [1].The term modulation is also used to describe certain types of baseband processing like Pulse amplitude modulation (PAM) or Pulse Code modulation (PCM) [2]. Modulation Systems for Satellite Communications: We can divide the modulation systems in two broad categories like Analogue Modulation and Digital Modulation Analogue modulation is Amplitude Modulation, Frequency Modulation and the phase Modulation. Digital Modulation is divided into several categories and each of those uses in specific purpose. Analogue Modulation: Let consider a sinusoidal wave f(t): f(t) = A cos {2*à Ã¢â€š ¬*f c(t)+ÃŽÂ ±}..(A) Where A is the amplitude, f c is the carrier frequency and theta is the phase of the wave with respect to the information signals. When the amplitude of the carrier wave is changed, then the wave is called amplitude modulated and scheme is known as the amplitude modulation. Likewise when frequency or phase of the wave is altered then it called frequency modulated and phase modulation respectively and techniques are known as frequency and phase modulation respectively [1]. Amplitude Modulation: As mentioned above, a carrier wave is said to be amplitude modulated when the amplitude of the carrier varies with respect to the baseband signal. An amplitude modulated signal can be given as V(t)= A{1+m(t)}cos (2*à Ã¢â€š ¬*fc) (1) In equation (1), m(t) is the message signal and the fc is the carrier frequency. A{1+m(t)} is the amplitude of the carrier and it varies accordance with the signal m(t). If m(t) is the sinusoidal signal and Am and fm is the amplitude and the frequency of the m(t) respectively, then it can be written as follows V(t)= A{1+Am sin2*pi*fm}cos (2*à Ã¢â€š ¬*fc) .(2) The spectral efficiency of V(t) can be obtain by expanding equation (3) and it can be shown that there are two side bands in the spectrum like upper and lower. The upper and lower sidebands consists of same spectral shape as that of the message signal m(t) [1]. The main advantages of the AM is that amplitude modulated carrier can be easily detected by using a simple envelop detector. An envelope detector is the simple large time constant RC circuit. But the difficulty is that AM modulation is rarely use for satellite communications because [1]: An amplitude modulated signal is very susceptible to the signal fluctuation It requires very high Signal to Noise ratio for desire amount of quality. AM is used in laser inter-satellite links (ISL) in an alternate form called ON-OFF keying. There are two forms of AM systems: Double Side Band Suppressed Carrier (DSB-SC) Single Side Band Modulation (SSB) In DSB-SC the carrier frequency is suppressed and only side bands are transmitted. In this case the amplitude of the wave does not follow the amplitude of the signal and as a consequence of that it reduces the simplicity of the demodulation in FM. DSB-SC is not used in the satellite communications but this technique is good for understanding the SSB modulation [1]. SSB is another alternative form of the AM systems. This technique is suitable for the application where the bandwidth is the premium. In AM modulation, both the side bands consist of baseband information and transmission of same information twice showing the redundancy. In this case, SSB modulation, this redundancy is cut-off by removing one of the sideband so the bandwidth of the RG signal is same as the bandwidth of the baseband signal. Sometimes the carrier is also removed then it is called SSB-SC (suppressed carrier) [1]. SSB is detected at the receiver end using synchronous detector. There are two factors playing an important role to make the SSB suitable for the satellite communications: occupied bandwidth and the required carrier to noise ratio. The most common application of the SSB in the satellite communication is to multiplex voice signals into a composite baseband signal. Another form of SSB is using in the mobile satellite communication is known as the ACSSB (Amplitude C ompanded SSB) because in mobile satellite service efficiency of the bandwidth is desired. Frequency Modulation: The FM systems are widely used in satellite communications. FM system is appropriate for those cases where the baseband signals are in analogue form. In FM, frequency of the carrier signal is varied with the message signal[1]. This scheme exploits where simple receivers are essential for transmission of the digital data[4]. An example is Inmarsat Paging system because an important requirement of the paging system is the need for simple, low-cost and rugged receiver [1]. The most common methods of modulation used in the fixed-satellite service are FM for analogue signals [5]. FM has been largely used in satellite communications. It is particularly convenient when a single carrier per transponder is used and where the constant envelope of the FM signals allows the power amplifiers to operate at saturation, thus making maximum use of the available power.[5] Digital Modulation: In digital modulation techniques baseband signals can be modulated by altering the one or more of its basic parameter: amplitude, frequency and phase. According to this there are three basic modulation schemes in digital modulation like Amplitude Shift Keying (ASK), Frequency Shift Keying (FSK) and Phase Shift Keying (PSK). There are many variations and combination of these techniques. The combination of ASK and PSK is also known as the QAM (Quadrature Amplitude Modulation).Table: 1 below showing list of some digital modulation schemes. Some of the schemes can be derived from more than one parent schemes [3]. Abbreviations Alternate Abbreviations Descriptive names FSK BFSK MFSK FSK Frequency Shift Keying (Generic name) Binary Frequency Shift Keying M-ary Frequency Shift Keying PSK BPSK QPSK OQPSK à Ã¢â€š ¬/4-QPSK MPSK PSK 4PSK SQPSK Phase Shift Keying (Generic Name) Binary Phase Shift Keying Quadrature Phase Shift Keying Offset QPSK, Staggered QPSK à Ã¢â€š ¬/4 Quadrature Phase Shift Keying M-ary Phase Shift Keying CPM SHPM MHPM LREC CPFSK MSK LRC LSRC GMSK TFM CORPSK FFSK Continuous Phase Modulation Single h (modulation index) phase modulation Multi h phase modulation Rectangular pulse of length L Continuous phase frequency shift keying Minimum phase shift keying, Fast frequency shift keying Raised cosine of pulse of length L Spectrally raised cosine pulse of length L Gaussian Minimum shift keying Tamed frequency shift keying Correlative PSK QAM ASK Quadrature amplitude modulation Amplitude shift keying QORC QOSRC SQORC Q2PSK UF-OQPSK TSI OQPSK SQAM XPSK Quadrature overlapped raised cosine modulation Quadrature overlapped square raised cosine modulation Staggered QORC Quadrature Quadrature phase shift keying Inter-symbol interference/Jitter free OQPSK Two symbol interleaved OQPSK Superposed QAM Cross-correlated QPSK Table: Digital Modulation using in satellite commiunications. As the advance in technology and limitation of analogue modulation it is now most of the satellite using digital modulation techniques and providing some advantages over analogue modulation like better performance, error detection and correction efficiency, signal to noise ratio etc. So in this paper focus are mainly given to the various types of digital modulation systems. We can divide digital modulation systems into two large categories [1]; Constant Envelop Modulation and Non- Constant Envelop Modulation and The constant envelop class is generally considered as the most suitable for the satellite communications because it minimizes the effect of non-linear amplification in the high power amplifier like TWTA (Travelling Wave Tube Amplifier) or KTA (Klystron Tube Amplifier). In this case the generic FSK is not suitable for satellite communication because it has very low bandwidth efficiency as compared to PSK systems [5].In this section of the report a brief description of different types of digital modulation systems using in satellite communication is given. PSK BPSK QPSK: In PSK system, envelop is constant but the phase changes discontinuously from symbol to symbol. There are two types of classic PSK schemes like BPSK (Binary PSK) and QPSK (Quadrature PSK). Generally, PSK modulation systems with M-ary signals can be used and its known as MPSK [5]. MPSK is more suitable than MFSK because it provides better Power Nyquest efficiency than MFSK. In mobile satellite communication, the most commonly used digital modulation system have been BPSK and different forms of QPSK. It is not surprising that higher order modulation are providing the better performance and efficient as well but they are more sensitive to the channel impairments. Recently, higher order PSK, 16-QAM is using for this purpose. [1] PSK modulation systems easily represented in the I-Q plane where I and Q axes are normal to each other. One point in I-Q plane is providing the information about the signal state [1]. PSK scheme include two basic techniques like BPSK and QPSK. In BPSK one binary code is represented by the two phases 0 and 180 where in QPSK two binary codes is represented by the four phases: 0, 90, 180 and 270. In multi level PSK, the higher the order the more requirement of power to achieve the same amount of performance [5]. PSK is using for satellite communication because PSK signal can be transmitted through the non-linear channel of a satellite and it depends on the proper choice of the modem filters [5]. Other types of modulation systems use in satellite communications are Quadrature schemes where the modulated signals are represented in terms of two channels like I and Q. Three schemes of Quadrature modulation are given below. OQPSK, offset QPSK or OKQPSK (offset keying QPSK), also known as the SQPSK (Staggered QPSK), is a modified form of QPSK. In the OQPSK, the value of Q and I channel not changing at the same instant because the value of the Q-channel baseband is delayed by the duration of one symbol. By using this property, OQPSK signals provide the reduction of the non-linear distortion when passing through non-linear element. So in this case, a better performance can be expected in the non-linear satellite channel as compared to the QPSK [7]. In OQPSK systems, maximum phase change is limited to 90. Its one of the reasons why OQPSK is advantageous for satellite channels and is used in satellite links [1]. MSK (minimum shift keying) is another coherent frequency shift keying modulation systems with modulation index 0.5. It also shows the non-linear property through a non-linear satellite channel and the signal has constant envelop.[5] MSK is spectrally more efficient than the QPSK and OQPSK because its spectrum has wider main lobe than QPSK and OQPSK [9]. QAM: It is seen that as there is a very limited bandwidth available for the satellite channels, the research for spectrally efficient modulation technique is essential for this application. Here QAM is used with the modified signal constellations for wideband satellite communication systems. [8] Because of its constant envelop to combat the non linearity of the satellite channel; M-ary phase shift keying is conventionally used in digital satellite communications systems. But when higher spectral efficiency is expected it cost more power than the other schemes. The main objective of modifying the QAM signal constellation is to reduce its sensitivity to the channel non linearity [8]. FSK: As described above, in Frequency Shift Keying systems, frequency is shifting in accordance with the message state change [1]. Binary Phase Shift Keying (BFSK) is the simplest form of the FSK allowed only two frequency states and this system can be extended to M level of frequency shifting then it is known as the M-ary FSK. In M-ary FSK N numbers of bits are combined to form a symbol. [1] M-FSK is a power efficient modulation technique which power efficiency can be increased by increasing the number of frequencies (M) at the cost of additional complexity and smaller bandwidth efficiency. This modulation system is found appropriate for some low rate and low power applications such as Global paging via satellite communications [10]. M-FSK can be used for in land mobile satellite communications where the numbers of user are stationary. It is valid for low data rate application like paging via satellites [10]. OFDM (Orthogonal Frequency Division Multiplexing) Modulation OFDM is a mature digital multi-carrier modulation technique has been used in physical layer of broadband wireless air interface standard like IEEE 802.11/Wi-Fi and 802.16/WiMax as well as digital video broadcast-Terrestrial DVB-T [11]. Simultaneously, OFDM modulation is attracting more attention for satellite communications and now it is using for DVB-TH. OFDM modulation systems also use in Military satellite communication. Coded Orthogonal Frequency division Multiplexing Modulation (C-OFDM) A COFDM modulation system is resistance to the frequency selective fading. This type of fading is seen in the wideband mobile communications. This system is useful for the digital audio and video broadcasting over a long distance. In future, C-OFDM systems would be one of the candidates for direct sound broadcast satellite systems [1]. Trellis Coded Modulation (TCM) Error correction coding and modulation are combined in Trellis coded modulation systems. To transmit information over the power-limited and band-limited channel, the modulation and the channel coding must be optimized jointly [12]. TCM with Octal Phase Modulation or 8-PSK 8-PSK is a constant amplitude modulation system with higher bandwidth efficiency. The first TCM application to satellite transmission occurred with the 8-PSK trellis codes. Using a 72 M Hz transponder bandwidth, transmission at up to 155.52 Mbits/s have been realized [5]. TCM with 8-PSK provides high bit rate which is essential in future for the high bit rate application like images, TV and HDTV services over the satellite transmission [5]. There are various forms of TCM like PTCM (pragmatic) and PPTCM (Punctured PTCM). The PTCM codes are interesting for satellite transmissions. As an example, a new coding systems using the PTCM 2/3-8PSK code concatenated with Reed -Solomon code in the INTELSAT IDR service and is expected to increase the capacity up to 25% base on the standard A earth station and INTELSAT VII space segment conditions [5]. As the demand is increasing for higher bandwidth efficiency, the QAM trellis codes could find the potential applications in HDTV satellite transmissions in the future. But the main limitation of trellis codes applying in the QAM using in the satellite communications is their non-constant amplitude and more distortion occur when pass through the NLA (Non-linear amplifier) [13]. A precise amplitude control must be used in the receiver end [5]. Trellis coded 16-PSK and 16-QAM modulation systems are used for satellite communications. But the fact is that when the modulation level increases, the constant envelop M-ary PSK modulation systems are inferior to the QAM systems. On the other hand, QAM suffers more distortion in the non-linear satellite communications channels [14]. QAM is suitable for geostationary orbit satellite channel with only Gaussian impairments because of being amplitude and phase modulated signal, QAM is more sensitive to the effects of interference and fading than MPSK [15]. Single Channel Per Carrier FM Modulation with syllabic Companding (SCPC FM) The main advantage of using SCPC FM modulation with syllabic Companding in satellite communication is to increase the limited capacity and this capacity increment is fully depends on the syllabic companding. The compadors in the transmission side take a wide volume of speech signals and reduce by the compressor with small amount of deviations. As a consequence of that in the same bandwidth it would be possible to employee more channels for transmission. And at the receiver end , the expender returns the original voice signals and during the speech pauses suppress the noise link[16]. This bandwidth efficiency can also be applied to the domestic satellite systems where the use of a small earth station and a large number of routes operating with few channels are important [16]. In future for the larger satellite (IntelSat IVA or V), the inefficient use of bandwidth of satellite channel by small carriers, especially in the transponder one of the factors which limits the total achievable capacity of bandwidth. In this case, the use of a SCPC companded FM would significantly increase the total capacity of the satellite bandwidth without increasing the total segment cost of the earth stations like other modulation systems [16]. From research it can be shown that the use of SCPC FM with compandors will significantly improve the economic scenario associated with the small earth stations. Wavelet Packet Modulation (WPM): WPM is a multicarrier modulation system like OFDM using Discrete Wavelet Transform (DWT). DWT is a transformation technique which is a presentation of the composite signal in time and frequency domain. So in WPM, packets structure is divided into time and frequency domain. So when any interference is realize, in TDMA or FDMA system all packets are degraded but in case of WPM, packets are keep away from the interference with the help of providing the appropriate packet structure [17]. Both WPM and OFDM are multicarrier modulation system but the difference is OFDM uses FFT to combine the transmission where WPM use DWT and Bit Error Rate (BER) of WPM is much better than the OFDM. Similarity between these modulation systems is High Peak to Average Power Ratio (PAPR). For improving the performance of OFDM, single carrier OFDM (SC-OFDM) is proposed where decreasing PARP was the main goal. It is seen that the PARP is also high in WPM so SC-OFDM can be used to improve efficiency of the WPM. SC-WPM also can be used by exploiting the principal of SC-OFDM [17]. Some experiment shows that the WPM is the effective modulation systems for satellite communications and with lower PARP, SC-WPM would enable the broadband satellite communications [17]. PARP performance of SC-WPM is superior to WPM and OFDM. The BER performance of the WPM is better than OFDM. Multi-Level Gaussian Frequency Shift Keying (MGFSK) MGFSK is a modulation systems use in the satellite communications. It also exploiting the technique of narrow band FM which has constant envelop throughout the signal. MGFSK is suitable for satellite communications where the transponders are in saturations and it is also useful for the transmitter where output amplifier is also saturated [18]. As compared to the 8PSK bandwidth efficiency (3 bit/s/Hz), MGFSK providing bandwidth efficiency is 6 bit/s/Hz [18]. BW efficiency of MGFSK is very similar to the 64 QAM but 64 QAM is not feasible to use in satellite communication because it requires highly linear and well-equalised satellite channels [18]. The key applications of MGFSK are in those satellites which trucking of ISP backbone traffic, satellite news gathering and military satellite applications. Pulse Code Modulation (PCM) Pulse code modulation system is another technique which is employed in the satellite communications. Here in PCM the main aim is to coding the analogue signal for digital representation and then transmitter by using digital techniques. In PCM, analogue signals are sampled in a periodic manner of time in a rate of Nyquest Sampling rate (twice the highest of baseband frequency) and then quantized in agreed manner. To keep the error in certain level, quantization step should keep as low as possible. [5] Different types of pulse code modulation are seen like DPCM and ADPCM. Other Modulation Systems use in Satellite Communications Delta modulation (AM), Pulse amplitude modulation (PAM), Pulse Time Modulation (PTM) etc. Spread Spectrum modulation systems are closely related to the PCM [1]. Conclusion: In this report it has been trying to make an overview of the modulation system used in the satellite communication channels. A different type of modulation systems has been described. The selection of modulation systems is depends on the various factors like type of the channels, constraints imposed by the earth stations (for fixed satellite, direct broadcast services and mobile satellite services), hardware limitations etc [1]. One fundamental characteristic of the satellite communications channels is the trade-off between the bandwidth and the power to obtain the received signal with certain level of quality. In case of the bandwidth limited channels, spectrally efficient modulation systems are used where penalty is paying for additional carrier power. In the power limited links, bandwidth efficient modulation is using which related to the hardware constraints as well. References: [1]. Raicharia, M.,[ 1995] Satellite Communication Systems: Design Principles, 2nd Edition, 1999, ISBN:0-333-74722-4, Macmillan Press Ltd,Baisingstoke, RG21 6XS. [2]. Couch, L W., Digital and Analogue Communication Systems, 5th Edition. 1997, Prantice Hall, Upperside river, NJ-07458, ISBN: 0-13-522583-3. [3] . Fuqin, Xiong., [August, 1994] Modem techniques in satellite communications, IEEE Communications Magazine, p. 84-98. [4]. Fthenakis, E., Manual of the Satellite Communications, McGraw-Hill Inc, 1984. [5]. Handbook of the Satellite Communications (HSC), 3rd Edition, pp: 242-275, http://www.scribd.com/doc/7047432/Handbook-on-Satellite-Communications, Last Visited 25.03.10 [6]. Taggart, D., Kumar, R., Cooper, L. , Wagner, N., Goo, G., Affects of Tone interference on the performance of QPSK and 8-PSK modulation in satellite communications, 2004, Arospace Conference, 2004. Proceedings. 2004. IEEE. [7]. Juing, Fang., [March, 1996] The other digital modulation techniques. ITU-R, Doc. 4HB/14, 25-28 March 1996. [8]. Kim, J., Liu, J,. Kwatra, S.C., Quadrature Amplitude Modulation Schemes with Modified Signal Constellations for a Wideband Satellite Communications, Military Communication Conference, 1995. MILCOM, 95. Conference Record, IEEE. [9]. Pasupathy, S. Mimimun Shift Keying : A Spactrally efficient Modulation, IEEE Communication Magazine, 1994, Vol 17, Issue:4, pp:16-22. [10]. Khalona, R.A., performance of a M-ary fsk modulation in a land mobine satellite communcaitin channel, Universatl personal Commuinication, 1994, pp: 430-434. [11]. Ludong, W; Jezek, B., ofdm modulation tecnnique for military satellite communciations, Military Communications Conference, 2008. MILCOM 2008. IEEE , 2008, pp: 1-7. [12]. Ungerboeck, G., [January, 1982] Channel coding with multilevel/phase signals, IEEE Trans. on IT-28. [13]. [Flash-TV] Flash-TV: Flexible and Advanced Satellite Systems for High Quality Television, with Interconnection with IBCNs, Race-II Project R2064. [14]. Benedetto, S.; Pent, M.; Zhang, Z., trellis coded 16-psk and 16-qam modualtion for satellite communicaiotns, Global Telecommunications Conference, 1988, and Exhibition. Communications for the Information Age. Conference Record, GLOBECOM 88., IEEE , 1988, Vol: 1, pp: 125-130. [15].Evans, B.G., Satellite Communication Systems, 3rd Edition, 2008, ISBN: 0-85296-899, Lightning Source UK Ltd. Milton Keynes. [16]. Evans ,B.G., Kernot ,R.J., Satellite-communication system employing single -channel /carrier frequency modulation with syllabic companding, IEE,1975, Vol: 122, Issue: 7, pp: 703-709. [17]. Sakakibara, H.; Okamoto, E.; Iwanami, Y., A Wavelet Packet Modulation Method for Satellite Communications, TENCON 2005, IEEE region 10, 2005, pp:1-5. [18]. Fitch, M., Boyd, I., Briggs, K., Steitiford, K., Gaussian multi-level FM for high-bandwidth satellite communications, University college of London (UCL), http://keithbriggs.info/documents/MGFSK_paper1_IB2_mrf-feb27.pdf, last visited: 27.03.10.

Friday, January 17, 2020

Ethics and Technology Essay

The biggest limitation of our existing system is its inherent inability to achieve its fundamental goal. Whatever happened to the dream of progress that modern technology would free people from drudgery, and everyone would be able to live in comfort, spending their time enriching the world and thinking great thoughts? Wasn’t that what we really set out to achieve? Toward that goal, we can now make virtually any region of the earth comfortably habitable. We can produce food and clothing in staggering quantities, at unbelievable rates of production, using very little labor in proportion to the output. We have greatly extended the life span of our species, and we know how to cure or eliminate the suffering of a great range of diseases. We can communicate around the globe in less time than it takes to hear the voice of someone across a room. An interesting question to consider is this: if the technology necessary to live this way really could be developed, would it result in such a society? Starting from our present society, I would say â€Å"absolutely not. † The technology that could easily feed the world would probably result in mass starvation. The competitive system can produce the tools we need to create a future of freedom and enlightenment, but unless the system evolves, it will work against our using those tools to the benefit of humanity. The system must evolve. We’re not spreading the benefits of advancing technology, we’re using it to exclude more and more people from the fruits of progress. Instead of laying off the â€Å"excess† workers and increasing the stress on those left behind, consider what would happen if we simply reduced the burden on everyone. We don’t need to throw out our traditions of free enterprise and individual responsibility. We just need to revisit our vision of progress and see where we want to go, and where we’re heading. Not all technology is hampering the society’s progress. Technology was developed to ease man’s work and provide him with a little help . It wasn’t invented so that we could just copy and paste an essay for our next paper, or download a ready made presentation from the internet or make google do all things for us. The web is what you make of it, you can’t blame technology for ruining your work ethics. It’s you who’s become super lazy and dependent I am from a time when technology is called â€Å"progress† and it was considered heretical to doubt its benefits. We tend to forget the years before antibiotics when people died from pneumonia and infections. We take for granted the warnings about kidney failure, liver damage and replacement therapy for intestinal flora that accompany today’s â€Å"bigger and better† medications. Technology has made our lives very easy, but it turn, has made us lazy. I believe that if we continue to make and improve technology, there can be some really useful inventions. However, we can make sure that the improvements don’t make us lazy, in very simple ways. We can ask ourselves, does this pen that writes down our thoughts and tells us how to spell correctly really need to be in everyone’s daily lives? Technology moves at a pace that can easily outrun ethical standards surrounding its use. The effects of technology on work ethics move at a similar pace with employers moving to establish ethical boundaries that seem to infringe on employee privacy rights and restrict communication abilities. These tactics have led to courtroom battles, quick job terminations and complaints filed with the National Labor Relations Board. Special Purpose: To inform my audience of the negative effects by becoming too dependent on technology. Central Idea: By becoming too dependent on technology will give negative effects to our education, behavior and economic. Introduction– According to study conducted by a company called McCan Worldgroup, young people are obsessed with their technology until the point that they would rather lose one of their most important sense than to lose Facebook, the internet and their cell phones. â€Å"To them, losing the ability to explore and communicate via technology would be like a blind man losing his stick†. According to Oxford dictionary, technology means machinery or equipment developed from scientific knowledge. Do you realized how much we depend on technology?

Thursday, January 9, 2020

How Did The History Of Meroe Reflect Interaction With...

Meroe 1) How did the history of Meroe reflect interaction with neighboring civilizations? The way the history of Meroe reflected interaction with neighboring civilizations is they traded more often with their neighbors. That is how they received their fortune and power. 2) How was the decline of Meroe connected to the changing patterns of long-distance trade? The decline of Meroe was caused by deforestation because wood was needed to make charcoal for iron. The deforestation made Egypt’s trade go from the Nile Valley to the Red Sea which made the materials available to Meroe’s kingdom disappear. 3) What role did the environment play in their history? The role of Meroe’s environment made the people of the kingdom such as merchants, farmers etc less dependent on irrigation systems. The overall population did not need to live by the Nile unlike Egypt who was in need of the irrigation system. Axum 4) How does the development of Axum match the characteristics of second-wave (or classical) civilizations? The way the development of Axum matches the characteristics civilizations is it was different than most civilizations. Axum was one of the civilizations that had many centralized states, languages that were written, involved in trading etc that was important in the second-wave civilization. 5) How did the history of Axum reflect interaction with neighboring civilizations? Just like Meroe, Axum also traded with its neighbors which reflect the interaction with its neighboringShow MoreRelatedWorld History AP8768 Words   |  36 Pagesstimulated the exchange of ideas, cultures, and values among the peoples they conquered. †¢ All empires sought to foster an imperial identity that transcended more local identities and loyalties. †¢ All empires ultimately collapsed. 2. In what ways did these empires differ from one another? What accounts for those differences? †¢ Some empires sought to rule through local elites; other empires sought to rule with a more centralized power structure. †¢ Some empires were new; others drew on older traditions

Wednesday, January 1, 2020

Teamwork And Collaboration How It s Integrated Into...

QSEN: Teamwork and Collaboration Teamwork is simply stated as less me and more we. With teamwork and collaboration, many wonderful things can be achieved especially in the healthcare profession. Anesthesiologists, CRNAs, surgeons, and O.R. nurses were interviewed regarding quality and importance of collaboration. Each profession rated 81-96% high for the importance of collaboration (Dellinger, 2016). The purpose of this paper is to discuss teamwork and collaboration and how it relates to knowledge, skills, and attitude. Also, how it’s integrated into education, nursing practice, and nursing research. Teamwork and Collaboration Definition Teamwork and Collaboration is a function effectively within nursing and†¦show more content†¦According to QSEN (2014) analyzing differences in communication style preferences among patients and families, nurses and other members of the health team is important. Skills When nurses function as part of a unit, and when they act as part of a team, the job itself is easier and more efficient. (Ward, 2013). In order to be efficient, the health professional needs to incorporate skills into their daily job environment. Skills such as demonstrating commitment to team goals, following communication practices that minimize risks associated with handoffs among providers and across transitions in care, and act with integrity, consistency and respect for differing views. (QSEN, 2014). A nurse should initiate requests for help when appropriate to situation, initiate actions to resolve conflict, and communicate with team members. (QSEN, 2014). Attitude A bad attitude is like a flat tire! If you don’t change it, you’ll never go anywhere. A professional’s attitude is important in any career but it is highly valued in the healthcare profession. A nurse for example, should be able to appreciate importance of intra- and inter-professional collaboration, contribute to resolution of conflict and disagreement, and respect the unique attributes that members bring to a team. (QSEN, 2014). Importance of integrating Teamwork and Collaboration Education Educating nurses and future nurses