Thomas Hobbes’ Leviathan Essay Example for Free

Thomas Hobbes’ Leviathan Essay Thomas Hobbes’ â€Å"Leviathan† is one of the most influential socio-political works during his time, extending even up to contemporary times. I for one will not be surprised to know that, precisely because the book itself is widely read and contains thoughts which are uniquely presented. Other than being a ‘revolutionizing’ approach to view society and politics, the â€Å"Leviathan† also shares a new way of understanding the structure of the society. Hobbes’ argument essentially focuses on the presumption that human beings are selfish and hungry for power, desiring to preserve their lives away from the harms of the chaotic state of nature. If I lived during the time when the book was published, I certainly will be surprised to some extent after reading the book since those years were the years of strict conformity to the existing status quo among the nations. In the book, Hobbes speaks about a sovereign, a person who will make sure that the people in the society will be accorded their safety against the threats of others. This proves to be of help especially when in a chaotic state where people will not hesitate to harm others, or perhaps even kill, just to preserve their own lives. A ruler will have to make sure that, indeed, the security of the people will be preserved under all conditions. However, I find rather difficult for the people under the violence of the state of nature to arrive at the decision to have a specific leader. Given the dire conditions of that state, is it really possible to choose among them a leader without ever arriving at more violence precisely because each of them has desires to preserve their selves? This might be a possibility, I think, since a chaotic state might be very difficult to tame down, especially for a single person. Nevertheless, it seems that Hobbes answers this question by positing the idea that although humans are selfish and seek power, they still have fear for their lives, or that they have fear of a violent death. With this in mind, it may be pointed out that the fear of a violent death gives ample room for a chaotic state of nature to be managed in one way or another. But is fear of a violent death a necessary condition for the people to begin thinking of choosing a sovereign among their number? I think that this may not be the sole necessary condition precisely because fear of a violent death may only inhibit certain violent actions of humans in the state of nature. They may hinder themselves from killing others or from inflicting violence upon others, but this does not altogether extinguish their desire for power and the preservation of the self. In the end, the selfishness of humans will still take a large role in their lives and in their decisions. What if Thomas Hobbes is truly right when he argues that the fear of a violent death will cause humans to eventually enter into a social contract and choose a sovereign? It may only mean that humans are compelled to enter into a social contract because their desire to preserve their welfare overrides their desire for power. But if the sovereign has already been elected, will the sovereign not resort to a dictatorial type of leadership given that the sovereign has the highest power in the state? I believe the chosen sovereign may have the tendencies of putting up a dictatorial regime simply because he still has that desire for power and that to secure the leader’s position in the state, the leader will have to make certain that there will be no possibility of a power-grab. Since the sovereign now has higher powers in the state above everybody else, it will not be difficult for the sovereign to eventually declare a dictatorial rule so that the leader can deprive all those who will desire to replace him in his position the chances of doing so. It seems, then, that the dire circumstances during the state of nature still have certain trickles of influences in the state after the social contract. Reference Hobbes, T. (1997). Leviathan (1st Touchstone ed. ). New York, NY: Touchstone.

What Is The Most Effective Way To Discipline Student :: essays research papers

School is the battleground for too many participants. For most teachers and students, a main battlefield revolves around discipline. Maintaining good discipline is a necessary condition for establishing a classroom climate that is conducive to learning. There are many ways to provide discipline, but one of the most productive is motivating students because they care about what they are learning. Enthusiastic teachers who present their material in stimulating, meaningful ways motivate students. When students are actively learning content that has personal meaning for them, they have neither the time nor the energy to create discipline problems. Conversely, when students feel that they are passive receptacles for knowledge, they become bored, turned off, and find satisfaction in acting out. Stimulating lessons require competition, high-level thinking, working cooperatively, and create products that evoke pride. Teacher has to increase students’ response, ask more low-risk, open-ended questions, see that low-ability students have an equal chance to respond. Of course, it is not easy work. Only teachers, who love their work and give all their time to make their lessons in such way can increase interest of their students and therefore provide discipline. I used to work as a teacher in a school for children with difficult behavior. When I started my job, the question of discipline was the main. And only after I could concentrate students’ attention on mathematics, when I knew how to work with students with different ability at the same time, when I did not give them a moment for relaxation, the discipline problem was solved. Competition is highly stimulating and motivates students to achieve their best. When competition focuses on the means, or process, the results are rewarding and high levels of learning can be achieved. Teamwork is a positive experience. Winning is important as playing. In my practice, the process of playing always was stressed above the final score. I often used games without score that supplemented the more competitive activities. Cooperative learning or working in groups is very important as well. Students work together in small groups in the classroom.

Bluetooth Simulation

VIDYAVARDHINI’S COLLEGE OF ENGINEERING AND TECHNOLOGY ELECTRONICS AND TELECOMMUNICATION FINAL YEAR [2004-2005] A REPORT ON BLUETOOTH TECHNOLOGY PREPARED BY JANHAVI KHANOLKAR NAVEEN BITRA YASHESH MANKAD TABLE OF CONTENTS 1. INTRODUCTION 2. HISTORY 3. WHAT IS BLUETOOTH? 4. BLUETOOTH SPECIFICATIONS 5. BLUETOOTH NETWORKS 6. HOW DOES BLUETOOTH WORK? 7. BLUETOOTH PROTOCOL STACK 8. BLUETOOTH SECURITY 9. APPLICATIONS 10. MERITS AND DEMERITS INTRODUCTION: Bluetooth was originally conceived to replace the rat’s nest of cables typical in any PC setup today and this remains a compelling home application.However, as the Bluetooth evolved it became clear that it would also enable a totally new networking paradigm, Personal Area Networks (PANs)! With PAN technology a user will be able to organize a collection of personal electronic products (their PDA, cell phone, laptop, desktop, MP3 player, etc. ) to automatically work together. For instance the contact manager and calendar in the P DA, laptop, and desktop could all automatically synchronize whenever they are within range of each other). Over time PANs will revolutionize the user experience of consumer electronics.Finally, Bluetooth’s dynamic nature will also revolutionize connectivity to the rest of the world. Bluetooth will automatically discover devices and services nearby so available servers, internet access, printers etc. will automatically become visible to a Bluetooth device wherever it is. HISTORY: Bluetooth is an open specification for short range wireless voice and data communications that was originally developed for cable replacement in personal area networking to operate all over the world.By enabling standardized wireless communication between any electrical devices, Bluetooth has created the notion of a personal Area Network (PAN), a kind of close range wireless network that looks set to revolutionize the way people interact with the information technology landscape around them. In 1994 t he initial study for development of this technology started at Ericsson, Sweden. In 1998, Ericsson, Nokia, IBM, Toshiba, and Intel formed a Special Interest Group (SIG) to expand the concept and develop a standard under IEEE 802. 15 WPAN (Wireless Personal Area Network ).In 1999, the first specification was released and accepted as the IEEE 802. 15 WPAN standard for 1Mbps networks. The Bluetooth SIG considers three basic scenarios: †¢ The first basic scenario is the Cable Replacement ie. the wire replacement to connect a PC or laptop to its keyboard, mouse, microphone, and notepad. It avoids the multiple short range wiring surroundings of today’s personal computing devices. †¢ The second scenario is ad hoc networking of several different users at very short range in an area such as a conference room. The third scenario is to use Bluetooth as an AP to the wide area voice and data services provided by the cellular networks, wired connections or satellite links. Why th e name Bluetooth? The story of origin of name Bluetooth is interesting. †Bnluetooth† was the nickname of Harald Blaatand, 10th century Viking who united Denmark and Norway. When Bluetooth specification was introduced to public, a stone carving, erected from Harald Blaatand’s capital city Jelling was also presented. This strange carving was interpreted as Bluetooth connecting a cellular phone and a wireless notepad in his hands.The picture was used to symbolize the vision in using Bluetooth to connect personal computing and communication devices. What is BLUETOOTH? [pic] Figure1: Bluetooth system blocks The Bluetooth system consists of a radio unit, a link control unit, and a support unit for link management and host terminal interface functions (see Figure 1). The Host Controller Interface (HCI) provides the means for a host device to access Bluetooth hardware capabilities. For example, a laptop computer could be the host device and a PC card inserted in the PC is the Bluetooth device.All commands from the host to the Bluetooth module and events from the module to the host go through the HCI interface. The protocol stack is above the radio and baseband hardware, partly residing in the Bluetooth unit and partly in the host device. A Bluetooth solution can also be implemented as a one-processor architecture (embedded solution) where the application resides together with the Bluetooth protocols in the same hardware. In that case, the HCI is not needed. This is a feasible implementation for simple devices such as accessories or micro servers.Requirements of Bluetooth technology: †¢ If Bluetooth technology is to replace cables, it can not be much more expensive than a cable or nobody will buy it. †¢ Because Bluetooth technology is designed for mobile devices it must be able to run on batteries. So it must be very low power and should run on low voltages. †¢ It must also be lightweight and small enough not to intrude on the design o f compact mobile devices such as cellular phones, handsets etc. †¢ It must be as reliable as the cable it replaces and also it must be resilient. †¢ Bluetooth devices operate at 2. GHz in globally available, license free ISM band, which obey a basic set of power and spectral emission and interference specifications. THUS Bluetooth has to be very robust, as there are many existing users and polluters of this shared spectrum. Thus Bluetooth aims to be widely available, inexpensive, convenient, easy to use, reliable, small and low power. Specifications related with Bluetooth: |PARAMETER |VALUES | |Frequency Range |2. – 2. 4835 GHz | |Bandwidth of each channel |1MHz | |Data rate |1 Mbps | |Frequency hopping rate |1600 hops per seconds | |Range of operation |10-100 meters | Bluetooth system operates in 2. GHz Industrial Scientific Medicine (ISM) band. The operating band is divided into 1MHz spaced channels each signaling data at 1 Mbps so as to obtain maximum available channel bandwidth with chosen modulation scheme of GFSK (Gaussian Frequency Shift Keying). Using GFSK, a binary 1 give rise to a positive frequency deviation from the nominal carrier frequency while binary 0 gives rise to a negative frequency deviation. After each packet both devices retune their radio to a different frequency, effectively hopping from radio channel from radio channel.In this way Bluetooth devices use the whole of available ISM band and if transmission is compromised by interference on one channel, the retransmission will always be on a different channel. Each Bluetooth time slot lasts 625 microseconds giving rise to frequency hopping rate of 1600 hops per seconds. Generally devices hop once per packet. .For long data transmission, particular users may occupy multiple time slots using the same transmission frequency thus slowing instantaneous hopping rate to below 1600 hops/ sec. BLUETOOTH NETWORKS: PICCONETS AND SCATTERNET:The Bluetooth network is called a piconet . In the simplest case it means that two devices are connected (see Figure 2a). The device that initiates the connection is called a master and the other devices are called slaves. The majority of Bluetooth applications will be point-to-point applications. Bluetooth connections are typically ad hoc connections, which means that the network will be established just for the current task and then dismantled after the data transfer has been completed. A master can have simultaneous connections (point-to-multipoint) to up to seven slaves (see Figure2b).Then, however, the data rate is limited. One device can also be connected in two or more piconets. The set-up is called scatternet (see Figure 2c). A device can, however, only be a master to one piconet at a time. Support for hold, park, or sniff mode is needed for a device to be part of the scatternet. In these modes a device does not actively participate in a piconet, leaving time for other activities such as participating in another pic onet, for example. The master/slave roles are not necessarily fixed and can also be changed during the connection if, for example, the master does not have enough esources to manage the piconet. Master/slave switch is also needed in the scatternet. Master/slave switch support is not mandatory. Most of current Bluetooth implementations support piconets only. Point-to-multipoint support depends on the implementation Figure 2. Bluetooth piconet and scatternet scenarios: a) Point-to-point connection between two devices b) Point-to-multipoint connection between a master and three slaves c) Scatternet that consists of three piconets Modes of operation: In connection state, the Bluetooth unit can be in several modes of operation.Sniff, hold, and park modes are used to save power or to free the capacity of a piconet: Active mode: In the active mode, the Bluetooth unit actively participates on the channel. Sniff mode: In the sniff mode, the duty cycle of the slave’s listen activity ca n be reduced. This means that the master can only start transmission in specified time slots. Hold mode: While in connection state, the ACL link to a slave can be put in a hold (possible SCO links are still supported). In hold mode, the slave can do other things, such as scanning, paging, inquiring, or attending another piconet.Park mode: If a slave does not need to participate in the piconet but still wants to remain synchronized to the channel (to participate in the piconet again later), it can enter the park mode. It gives up its active member address. Park mode is useful if there are more than seven devices that occasionally need to participate in the same piconet. The parked slave wakes up regularly to listen to the channel in order to re-synchronize and to check for broadcast messages sent by the master.. FREQUENCY HOPPING :Bluetooth technology uses a frequency hopping technique, which means that every packet is transmitted on a different frequency. In most countries, 79 chann els can be used. With a fast hop rate (1600 hops per second), good interference protection is achieved. Another benefit is a short packet length. If some other device is jamming the transmission of a packet, the packet is resent in another frequency determined by the frequency scheme of the master. This scenario is depicted in Figure 3 where packets of device 1 (colored packets) and device 2 (banded packets) are trying to use the same frequency.Note that this case only refers to situations where there are two or more simultaneous active piconets or a non-Bluetooth device using the same frequency in range. The error correction algorithms are used to correct the fault caused by jammed transmissions Figure 4. Three-slot and five-slot long packets reduce overhead compared to one-slot packets. 220  µs switching time after the packet is needed for changing the frequency. Subsequent time slots are used for transmitting and receiving. The nominal slot length is 625 (s.A packet nominally c overs a single slot, but can be extended to cover three or five slots, as depicted in Figure 4. In multi-slot packets the frequency remains the same until the entire packet is sent. When using a multi-slot packet, the data rate is higher because the header and a 220 (s long switching time after the packet are needed only once in each packet. On the other hand, the robustness is reduced: in a crowded environment the long packets will more probably be lost HOW DOES BLUETOOTH WORKS? Bluetooth devices have 4 basic States.They can be a Master (in control of a Piconet — represented by a large blue circle above), an Active Slave (connected and actively monitoring/participating on a Piconet — medium orange circles), a Passive Slave (still logically part of a Piconet but in a low power, occasionally monitoring but still synchronized, inactive, state — medium gray circles), and Standby (not connected to a Piconet, occasionally monitoring for inquiries from other devices, but not synchronized with any other devices — small white circles). IN IDEAL STATE Bluetooth devices initially know only about themselves and in this state they will be in Standby mode.Standby is a passive mode where a Bluetooth device listens on an occasional basis performing what are called Inquiry and/or Page Scans for 10 milliseconds out of every 1. 28 seconds to see if any other Bluetooth devices are looking to communicate. Passive behavior is inherent to half of Bluetooth’s states and is a key mechanism to achieving very low power. In Standby mode the Bluetooth device’s occasional attention reduces power consumption by over 98%. While all of the Bluetooth devices in the same mode it is important to note that they are NOT synchronized or coordinated in any way.Thus they are all listening at different times and on different frequencies. [pic] Enquiry and page procedures lead to connections ENQUIRY: Inquiry is how a Bluetooth device learns about other devices that are within its range. In the illustration above Node A executes a Page Function on the BT Inquiry ID and receives replies from other devices. Through these replies device A learns the explicit identity of these other devices (i. e. their unique Bluetooth device ID). During the Inquiry process device A continuously broadcasts the Page command using the reserved Inquiry ID which identifies it as as a Page Inquiry.These broadcasts are spread across a standard pattern of 32 Standby radio frequencies which all devices in Standby mode monitor on an occasional basis. Over a duration of some seconds it is certain that every Standby device within range will have received the Inquiry Page even though they are not synchronized in any way. By convention these nodes will respond with a standard FHS packet that provides their unique BT ID and their clock offset. With these parameters the Inquiring node can effect low latency synchronized connections.Node H (the dotted circle above) illustra tes how a Bluetooth device can be programmed to remain anonymous (Undiscoverable in BT jargon). This is a user controlled feature that suspends Inquiry Scanning, and thus device A’s Inquiry Procedure cannot discover Device B It is important to note that device H will continue to support Page Scanning however, and thus a user’s other personal devices (i. e. PAN) can penetrate this barrier by Paging directly to its unique Bluetooth ID. This is information that PAN devices can be configured to know and remember thus enabling private collaboration even when devices are undiscoverable.PAGING: In its general form the Page command establishes a formal device to device link between a Master (the originator) and a Slave. Master/Slave connections in Bluetooth are referred to as a Piconet. To create the piconet device A broadcasts the Page command with the explicit device ID of the target Slave (B in the illustration above) which was learned earlier through an Inquiry Procedure. Further, this connection can be very low latency if the Inquiry data is recent (and thus synchronization can be accurate), but the process will simply take longer if this is not the case.All Bluetooth devices except B will ignore this command as it is not addressed to them. When the device B replies, device A will send it an FHS packet back and assign it an Active Member Address in the Piconet. As an Active Slave device B will begin continuously monitoring for further commands from device A in synchronization with device A’s hopping pattern and clock offset. Further, standard Piconet activity continuously updates the clock offset data keeping the synchronization extremely accurate. Thus the Master and Slave states are not low power but exhibit very low transaction latencies. EXPANDING A PICCONET:Through successive Page commands a Bluetooth Master can attach up to 7 Active Slaves. 7 is a hard limit as only 3 bits are allocated in Bluetooth for the Active Member Address (AMA) w ith 000 reserved for the Master and the remaining addresses allocated to Slaves. Practically, 7 is more than sufficient given Bluetooth’s modest performance and dynamic configurability. Again, all Active Slaves to A continuously monitor for further commands addressed to them in synchronization with device A’s hopping pattern. PARKING: Parking is a mechanism that allows a Bluetooth Master to connect to an additional 256 devices. 56 is a hard limit as 8 bits are allocated in Bluetooth for the Parked Member Address (PMA). To Park a device the Bluetooth Master issues a Park command to an Active Slave and assigns it a PMA. This Slave then enters the Parked mode and surrenders its AMA. As a Parked Slave the device will revert to a passive mode and only monitor for commands on an occasional basis. The difference between Standby and Parked however is that the Slave will remain synchronized to the Master’s hopping pattern and regularly update its clock offset. Thus this device can be reconnected at any time with a minimum latency.BLUETOOTH PROTOCOLS: Protocols are needed to implement different profiles and usage models. Every profile uses at least part of the protocol stack. In order to achieve interoperability between two Bluetooth devices, they both must have the same vertical profile of the protocol stack. Bluetooth Core Protocols Baseband and Link Control together enable a physical RF link between Bluetooth units forming a piconet. This layer is responsible for synchronizing the transmission-hopping frequency and clocks ofdifferent Bluetooth devices [Whitepaper1, p. ]. Audio is routed directly to and from Baseband. Any two Bluetooth devices supporting audio can send and receive audio data between each other just by opening an audio link . Link Manager Protocol (LMP) is responsible for link set-up (authentication and encryption, control, and negotiation of baseband packets) between Bluetooth devices and for power modes and connection states of a Bluetooth unit. Logical Link Control and Adaptation Protocol (L2CAP) takes care of multiplexing, reassembly, and segmentation of packets.Service Discovery Protocol (SDP) is needed when requesting device information, services, and the characteristics of other devices. Devices have to support the same service in order to establish a connection with each other. Cable Replacement Protocol RFCOMM emulates RS-232 signals and can thus be used in applications that were formerly implemented with a serial cable (e. g. , a connection between a laptop computer and a mobile phone). Telephony Protocol Binary (TCS-BIN) defines the call control signaling for the establishment of speech and data call between Bluetooth devices.AT commands provide means for controlling a mobile phone or a modem. Adopted Protocols OBEX (Object Exchange) is adopted from IrDA. It is a session protocol that provides means for simple and spontaneous object and data transfer. It is independent of the transport mechanism an d transport Application Programming Interface (API). TCP/UDP/IP is defined to operate in Bluetooth units allowing them to communicate with other units connected, for instance, to the Internet. The TCP/IP/PPP protocol configuration is used for all Internet Bridge usage scenarios in Bluetooth 1. and for OBEX in future versions. The UDP/IP/PPP configuration is available as transport for WAP. PPP in the Bluetooth technology is designed to run over RFCOMM to accomplish point-to-point connections. PPP is a packet-oriented protocol and must therefore use its serial mechanisms to convert the packet data stream into a serial data stream. The Wireless Application Protocol (WAP) stack can reside on top of RFCOMM (based on LAN Access Profile) or on top of L2CAP (based on PAN Profile). The latter reduces overhead and is likely to become the preferred solution for WAP over Bluetooth.Wireless Application Environment (WAE) hosts the WAP browser environment. Dial up networking (DUN) profile protocol stack: DUN profile is inside the Serial Port Profile and therefore partly reuses the capabilities of the Serial Port Profile. For the DUN Profile, there are two device configurations (roles): †¢ Gateway (GW) is the device that provides access to the public network (typically mobile phones and modems) †¢ Data terminal (DT) is the device that uses the dial-up services of the gateway (typically PCs) The DUN Profile needs a two-piece protocol stack and an SDP branch.PPP over RFCOMM is needed for transferring payload data. AT commands are delivered over RFCOMM to control the modem (mobile phone). The application on top of the stack is either a driver application on a PC (data terminal) or the modem emulation on a phone (gateway). Bluetooth security: secret key All Bluetooth devices (master and slave) share a secret key in a particular system. This key is used during the authentication and encryption process. This key is not transmitted over the channel but is rather in-built b y the manufacturer. AUTHENTICATIONAuthentication ensures the identity of Bluetooth devices. Authorization is a process of deciding if a device is allowed to have access to a specific service. User interaction may be required unless the remote device has been marked as â€Å"trusted. † Usually the user an set authorization on/off to every remote device separately. Authorization always requires authentication. Authentication in Bluetooth is performed by an encryption engine which uses the SAFER+ algo. This algorithm requires the following: †¢ Number to be encrypted or decrypted †¢ master address †¢ Master clock secret key shared by master and slave. A random number is generated by the encryption engine using various keys. This random number is encrypted by the master using the secret key. This number is also sent to the slave. The encrypted reply of the slave is compared with the master encrypted data. If it is a match then the slave is authentic. BONDING AND PAI RING Pairing is a procedure that authenticates two devices based on a common passkey, thereby creating a trusted relationship between those devices. An arbitrary but identical passkey must be entered on both devices.As long as both devices are paired, the pairing procedure is not required when connecting those devices again (the existing link key is used for authentication). Devices without any input method, like headsets, have fixed passkeys. When two devices are linked with a common link the connection is called as bonding. There are two types of bonding: †¢ Dedicated bonding: Used to create and exchange a link key between two devices. †¢ General bonding: Data over the link is available for higher layers. ENCRYPTION Encryption protects communication against eavesdropping.For example, it ensures that nobody can listen to what a laptop transmits to a phone. Encryption demands the following: †¢ Negotiating encryption mode †¢ Negotiating key sizes-The key size coul d vary from 8 to 128 bits †¢ Starting encryption †¢ Stopping encryption SECURITY LEVELS A trusted device has been previously authenticated, a link key is stored, and the device is marked as â€Å"trusted† in the security database of a device. The device can access Bluetooth services without user acceptance. An untrusted device has been previously authenticated, a link key is stored, but the device is not marked as â€Å"trusted. Access to services requires acceptance of the user. An unknown device means that there is no security information on this device. This is also an untrusted device. Security Level of Services Authorization required: Access is only granted automatically to trusted devices or untrusted devices after an authorization procedure (‘Do you accept connection from remote device? ’). Authentication is always required. Authentication required: The remote device must be authenticated before connecting to the application. Encryption required : The link must be changed to encrypted before accessing the service.It is also possible that a service does not require any of these mechanisms. On the other hand, the application (service) might have its own user authentication mechanisms (a PIN code, for example). APPLICATIONS: 1. Bluetooth in the home will ultimately eliminate most every cable related to consumer electronics (except power). Your PC, scanner, and printer will simply need to be within 10 meters of each other in order to work. Your PDA, digital camera, and MP3 player will no longer need a docking station to transfer files or get the latest tunes (the exception will be to recharge, that power thing again).And, your home stereo and other equipment will join the party too. On the telephone front your cell phone will synchronize its address book with your PC and function as a handset to your cordless phone in the house (answering incoming calls to your home number and calling out on the cheaper land line too). Finally, even though its only 720Kbps, Bluetooth is still pretty fine for broadband internet access since DSL and cable modems are typically throttled to about 384K anyway. Bluetooth access points could well be as ubiquitous as 56K modems in 2 or 3 years. . On the road much of your Bluetooth PAN goes with you. Even when your laptop is in your briefcase and your cell phone is in your pocket they will be able to collaborate to access e-mail. And, next generation cell phones featuring Bluetooth and General Packet Radio (GPR) technology will function as a wireless modems with internet access at 100Kbps+. With such performance it is likely web based e-business will flourish and these devices will become the most prevalent Bluetooth access points.This may well be the Killer App that ensures Bluetooth’s widespread adoption and success. When you are literally on the road your car will join your PAN too. Here your cell phone may operate in a hands free mode using the car audio system and an i n-dash microphone even while comfortably in your pocket. Or you may use a wireless Bluetooth headset instead. And, your MP3 player will likely play music in 8 speaker surround sound, rip music right off of an FM broadcast, or record your phone calls for later review. And all without wires!!!Fixed land line access points (supporting up to 720Kbps) such as a pay phone in the airport terminal or lounge, or the desk phone in your hotel, will provide true broadband access in these strategic locations. Also look for the pay phone to evolve to compete for your cell phone calls too with its low cost land lines. In the world of deregulation and open competition future smart phones may even put your calls out for bid and channel the traffic over the carrier offering the lowest cost! 3. Telephone applications †¢ Hands free use †¢ File synchronization †¢ Calendars †¢ Contact management Land line I/F for voice and data 4. Consumer applications †¢ File transfer †¢ MP 3 †¢ Digital pictures †¢ Peripheral connectivity †¢ Keyboard/mouse/remote †¢ Printer ADVANTAGES: 1. Point to point and point to multiple links 2. Voice and data links 3. Compact form factor 4. Low power 5. Low cost 6. Robust frequency hopping and error correction 7. Profiles ensure application level 8. High level of security through frequency hopping, encryption and authentication 9. Non directional 10. Unlicensed ISM band LIMITATIONS: 1. 8 Devices per piconet with limited extension via scatternet 2.Short range 3. No handover facility 4. Maximum data rate of 723. 2 Kb/s 5. occupies the crowded ISM band 6. Slow connection setup References: †¢ Bluetooth 1. 1 —Jenifer Bray †¢ Wireless Communication -Krishnamurthy †¢ Bluetooth Specifications, Bluetooth SIG at http://www. bluetooth. com †¢ Bluetooth Protocol Architecture v1. 0, Riku Mettala, Bluetooth SIG, August 1999 http://www. bluetooth. org/foundry/sitecontent/document/whitepapers_presen tations †¢ Bluetooth Security Architecture, Thomas Muller, Bluetooth SIG, July 1999 http://www. bluetooth. rg/foundry/sitecontent/document/whitepapers_presentations †¢ Comprehensive Description of the Bluetooth System v0. 9p, Dan Sonnerstam, Bluetooth SIG, May 1998 http://info. nsu. ac. kr/cwb-data/data/ycra2/comprehensive_description_of_the_BT_system. pdf †¢ Bluetooth Technology Overview, version 1. 0, April 2003 http://forum. nokia. com ———————– [pic] Digital Camera Computer Scanner Home Audio System MP3 Player PDA Cell Phone Operational States Master Active Slave Parked Slave* Standby* ON THE ROAD Laptop PDA Cell Phone MP3 Player Headset Hotel Phone & Access Point

Hypertension High Blood Pressure - 1938 Words

HYPERTENSION Summer 2015 Bhavneet K. Singh High blood pressure Definition: The heart is supplies the organs and tissues of the body with blood and nutrients it carries. It pumps blood into the blood vessels of the circulatory system. The blood that is pumped into these vessels puts pressure on the walls of the vessels. When the heart muscle contracts during each beat, the pressure rises as well. Blood pressure may be different at different times of the day. It is usually higher when someone first wakes up, after exercise, or when under stress. Having higher blood pressure for short amounts of time is normal, but when blood pressure stays high for most of the time, it can cause serious health problems. High blood pressure, also called hypertension, is a serious medical condition. It is defined as a chronically increased systemic arterial pressure. It happens when the force of the blood pumping through the arteries is too strong. About 7 million people die each year in the United States from illnesses caused by high blood pressure. Blood pressure is measured in units of â€Å"millimeters of mercury† written mm Hg. When measuring blood pressure, there are two different values. Systolic blood pressure is taken while the heart muscle is contracting and pumping oxygen-rich blood into the blood vessels. Diastolic blood pressure is taken while the muscle is relaxing and refilling with blood. Blood pressure measurements are given in pairs, with the upper (systolic) value firstShow MoreRelatedHypertension And High Blood Pressure1703 Words   |  7 PagesHypertension Hypertension is referred to as high blood pressure. Hypertension is frequently asymptomatic in the early stages, and the initial signs are often vague and nonspecific. They include fatigue, malaise, and sometimes morning headache. Consistently elevated blood pressure under various conditions is the key sign of hypertension. Because of the insidious onset and mild signs, hypertension is often undiagnosed until complications arise and has been called the â€Å"silent killer.† The complicationsRead MoreHypertension : High Blood Pressure1124 Words   |  5 Pages Hypertension (High Blood Pressure) is a sickness that a great many individuals of different varieties are influenced by. In spite of the fact that stress and emotional pressure can incidentally expand pulse; however it would not be considered as hypertension. Hypertension normally is there with no manifestations. It may happen and stay inconspicuous for a long time. Individuals, until told by a therapeutic doct or by large disregard hypertension. Individuals are not mindful of how hypertensionRead MoreHypertension : High Blood Pressure Essay1266 Words   |  6 Pages Many of my clients with high blood pressure take premium Omega-3 oils, and have reported benefits such as decrease in spikes, normalized pressure readings and other cardiovascular beneficial effects. Hypertension is High Blood Pressure, and blood pressure is defined as: (from Wikipedia) ... the force exerted by circulating blood on the walls of blood vessels, and constitutes one of the principal vital signs. The pressure of the circulating blood decreases as blood moves through arteries, arteriolesRead MoreHypertension : High Blood Pressure1192 Words   |  5 PagesHypertension is unusually high blood pressure that affects nearly 600 million people around the world. So many people are affected because hypertension rarely shows any symptoms while damaging the eyes, brain, heart, and kidneys. There is no known cure for hypertension although it causes five million premature deaths per year. One of the most effective hypertension treatments is homeopathy, a branch of alternative medicine based on the idea that the body has the ability to heal itself. There is evidenceRead MoreHypertension : High Blood Pressure1157 Words   |  5 PagesHypertension (high blood pressure) is a major health issue worldwide, in addition to the vast amounts of strokes, chronic kidney diseas es (CDK), and heart failures. However, organized hypertension prevention and control interventions have demonstrated to decrease the detrimental outcomes. Additionally, the management of salt consumption also displays a decrease of blood pressure towards the population at risk. A global-base assessment of hypertension programs and salt consumptions was performedRead MoreHypertension : High Blood Pressure2401 Words   |  10 PagesBackground Introduction Hypertension is abnormally high blood pressure; a diet high in salt may predispose to hypertension. An increase in levels of systolic and diastolic blood pressure has been associated with an increased risk of developing coronary heart disease (CHD), cerebral vascular disease (stroke) and peripheral vascular disease. Within the western countries, those associated with a higher economic status, hypertension accounts for around 17% of deaths. A positive correlation between intakeRead MoreHypertension : High Blood Pressure1881 Words   |  8 Pages Hypertension is commonly known as high blood pressure. What does it mean to have high blood pressure? Blood pressure can be defined as the amount of blood the heart pumps and the amount of resistance to blood flow in the arteries. It is when the systolic reading is greater than 140 and the diastolic is greater than 90. Systolic is blood pressure when the heart contracts while diastolic is the time when the heart is relaxed. Primary care physicians are accustomed to seeing cases of hypertension.Read MoreHypertension And High Blood Pressure1767 Words   |  8 PagesHypertension Hypertension (or high blood pressure) is a condition that increases the chance of developing heart disease, which is the number one leading cause of death in the United States. Hypertension affects approximately 75 million adults in America, which translates to 29% of the population.1 Hypertension is a chronic condition that results with lasting blood pressure readings of 140/90 and higher and affects the cardiovascular system in the human body. The cardiovascular system is comprisedRead MoreHypertension ( Htn ), Or High Blood Pressure1000 Words   |  4 PagesHypertension (HTN), or high blood pressure, is the leading cause of cardiovascular disorders and is one of the most common health issues among adults. It affects nearly 50 million people in the United States and over 1 billion around the world (Porth, 2015, p. 425). Blood pressure is defined as the force exerted on arterial walls as blood is pumped from the left ventricle of the heart. A certain amount of pressure is necessar y in order to perfuse blood throughout the whole body. Normal blood pressureRead MoreEffects Of Hypertension On High Blood Pressure999 Words   |  4 Pages1DEFINITION: Hypertension has been defined as systolic pressure 140mmhg and diastolic pressure 90mmhg based on the average of two or more correct blood pressure measurement taken during two or more contacts with a health care provider (Chobania et al,2003). 2.2.2 CLASSIFICATION: It has been classified by the seventh report of the Joint National Committee on Prevention ,Detection, Evaluation and treatment of high blood pressure(JNC, 2003) TYPE MEASUREMENT(mmHg) Normal 120/80 Pre-hypertension 120/80-139/89