Peranti output ialah mana-mana kelengkapan perkakasan komputer yang digunakan untuk menyampaikan hasil pemprosesan data yang dilakukan oleh sistem pemprosesan maklumat(seperti komputer) kepada dunia luar, manakala input/output (I/O) merujuk kepada komunikasi tersebut. Sebaliknya, output ialah syarat atau data yang dihantar oleh sistem ke luar, berbeza dengan input yang merupakan isyarat atau data yang dihantar kepada sistem.
eranti input (peranti masukan) ialah mana-mana perkakasan komputerpersisian yang memberikan data dan isyarat arahan kepada sistem pemprosesan maklumat (seperti komputer). Antara contoh-contoh peranti input adalah seperti di bawah:
December 21 2012 Predictions – The End of The World 2012?
Until a couple of years ago there were not that many people who were acquainted with the end of the world 2012 prophecy that was put forward by many scholars who studied the end of the Mayan long calendar. This Long Count calendar has lasted for five thousand one hundred and twenty five years, and although the end of the calendar leads to many different interpretations, one of the most popular is the belief that at the end of this cycle the world (or humanity’s existence) will come to an abrupt end on December 21 2012.
In order to fully understand the 2012 end of the world predications, then you should first understand the calendar that is at the center of this controversy. The current cycle, or baktun, of this calendar began on August 13th, 3114 B.C. This marked the end of the last period and the beginning of the current one. The baktun that we are currently living in is the thirteenth, and the end of this cycle is one that has been considered to have a large level of importance to the Mayan people, which is why so many people have come to the conclusion that this cycle’s end is one that will mean the end of the world as we know it.
While there is no definite proclamation of how the end of the world 2012 predictions will happen, those who have studied this calendar claim that the long calendar was created in order to correspond with a long term astronomical prediction by the Mayan people. This has led some to believe that this end of the world scenario will play out in a manner that has something to do with something from beyond this world. While this correlation to something that is going on in outer space is not a definite thing, for some it comes from a basic understanding of Mayan culture and their unique understanding of astronomical phenomena and planetary alignments.
The Truth About Planet X – Nibiru
Something else that has been considered is the belief that the 2012 end of the world will come to Earth not through some planetary force outside of our galaxy, but through the power of our own sun. Some who have studied the timing of the 2012 prophesy and combined this knowledge with an understanding of the solar system believe that the end will come via a large solar flare. This flare will come about because of the infiltration of the orbits of the planets in our solar system by an outside orbiting planet that the Sumerians and the Babylonians referred to as Nibiru, and is sometimes referred to by modern scientists as Planet X. Those who subscribe to this theory believe that Nibiru only orbits through our system once every three thousand six hundred years.
In addition to this, these cultures believed that there were a race of people who lived on Nibiru that were known as the Anunnaki. According to their creation mythology this superior race of beings came to Earth and genetically engineered human beings. They did this because they needed to get gold ore from our planet in order to help save their own environment. The humans that they created helped them by mining the gold from Africa. The basis for this mythology was found in ancient writings that were recently uncovered in relation to the ancient Sumerians, and they documented this creation in detail in their writings. If they are correct, then the end of the world 2012 that is depicted in the Mayan calendar will also coincide with the return of the Anunnaki. In essence, it would be the return of our creators, and this is also something that is closely linked in with the belief that the Mayan calendar signals the forthcoming Apocalypse.
According to this 2012 end of the world philosophy, when this planetary body re-enters our system it will cause massive disruptions in the orbits of Jupiter, Uranus, Venus, and Earth. When Nibiru crosses our orbit they believe that it will cause the gases in Jupiter to ignite because it will get too close to the sun and the precarious balance that keeps its gas structure in check will be lost, therefore causing Jupiter to turn into a secondary sun. In combination with this, the solar flares that are released from the sun on a naturally reoccurring cycle are set to peak during the year 2012. It is believed that this occurrence in combination with the cycle of Nibiru will cause a massive amount of damage to the planet on a level that has never been seen before.
Planetary Alignment on December 21 2012
However, there are others who contend that the end of the world 2012 prophesy actually refers to a very rare planetary alignment that will occur during the winter solstice on december 21 2012. At this time the entire Milky Way (including the earth and the sun) will align at a point that is known as the galactic equator. This alignment is so rare that it only happens every twenty five thousand years. It is thought that this rare planetary alignment could signal a shift in the magnetic poles. This polar shift has happened before in the distant past, and if it were to happen now it would cause massive destruction across the globe. Some claim that the reason the Mayan long calendar ends on this exact date is that something is going to happen in combination with this alignment, the introduction of Nibiru, and the solar flares. It can’t be a coincidence that all of these things are scheduled to happen at the same time that the Mayan calendar is set to come to its conclusion, can it?
If nothing else the 2012 end of the world prophesy that is brought about by the Mayan calendar does bring with it several questions about this culture’s knowledge of celestial events and happenings that they could not have possibly understood, let alone have mapped out to the extent that they did. Their understanding of the solar system, the planetary alignments, and other important events is something that cannot be easily explained or understood by most people who have studied this rare Mayan philosophy.
The end of the world 2012 scenario is one that frightens many people, but this does not have to be the case. If you are interested in finding out more about the theories and philosophies that the 2012 doomsday prophesy is founded on, then you visit the link below to find out more about the end of the world and what you can do to help your family survive any number of disasters. On top of this you can get a complete three hundred and sixty degree view of the processes of the 2012 countdown, including a special bulletin that will keep you up to date on everything that is related to this upcoming date and the disastrous implications it brings with it. So, if you are someone who is looking to make sure that they stay ahead of the danger and keep on top of new developments on the end of the world 2012, then this site is the perfect thing to keep you informed and prepared to december 21 2012.
Dikomando Jaringan Perang Angkatan Laut AS, ancaman terbesar terhadap jaringan komputer AS berasal dari hacker China. Menurut laporan dari Federal Computer Week (FCW), hacker China "terus-menerus melancarkan perang habis-habisan terhadap jaringan Departemen Pertahanan."
Masalah ini mulai menjadi berita utama pada 12 Januari ketika Google memuat pada blog resminya bahwa mereka mendeteksi "serangan sangat canggih dan bertarget" yang berasal dari China yang mencuri kekayaan intelektual. Penyelidikan lebih lanjut menemukan bahwa serangan juga menargetkan sedikitnya 20 perusahaan besar lainnya dan juga akun e-mail Google dari aktivis HAM China.
Pengumuman mengakibatkan respons internasional, dan Menlu AS Hillary Clinton mendesak China untuk menyelidiki serangan tersebut. Namun, AS telah menyadari akan kegiatan cyberwarfare China selama beberapa tahun.
Hans Remberg, wakil president dari intelijen domestik Republik Federal Jerman, menuduh China yang mensponsori serangan komputer "hampir setiap hari."
Menurut laporan Departemen Pertahanan AS kepada Kongres, Remberg mengatakan bahwa, "Di seluruh dunia RRC (Republik Rakyat China) secara intensif mengumpulkan data politik, militer, perusahaan-strategis, dan informasi ilmiah dalam rangka mengatasi kesenjangan teknologi China secepat mungkin."
Laporan Departemen Keamanan menambahkan bahwa serangan dari China memiliki tingkat kecanggihan yang lebih tinggi dan terorganisasi daripada hacker dari negara lain, dan "konflik telah mencapai tingkat serangan habis-habisan."
"Mereka akan memanfaatkan apa pun dan segalanya," kata seorang pejabat senior memberitahu FCW dalam laporannya. "Sulit untuk dipercaya kalau itu tidak dikendalikan pemerintah."
Serangan memiliki berbagai tujuan, termasuk mencuri teknologi, pengumpulan intelijen, dan mencuri informasi dari Departemen Keamanan.
Ancaman utama dalam serangan cyber China, selain untuk mencuri informasi tingkat tinggi militer AS informasi dan operasinya, adalah bahwa mereka juga menanam virus tidur yang dapat diaktifkan di lain waktu.
"Sebuah laporan militer China menyatakan bahwa China berencana untuk dapat memenangkan sebuah 'perang informasi' pada pertengahan abad ini," kata laporan FCW.
Sebuah Strategi yang lebih luas
Partai Komunis China (PKC) telah berulang kali membantah tuduhan serangan cyber terhadap AS, negara-negara lain, dan pebisnis, sering menyebut tuduhan rasis atau melawan China. Setelah serangan baru-baru ini di Google, sebuah pernyataan yang diterbitkan oleh juru bicara dari Departemen Perindustrian dan Teknologi Informasi China mengatakan tuduhan "tidak berdasar dan bertujuan untuk merendahkan China."
Sebagian dari kekuatiran adalah kurangnya transparansi dalam pembangunan kemampuan perang cyber dan teknologi rezim China. Ini sejalan dengan kurangnya transparansi rezim dalam pengeluaran militer dan pembangunan secara keseluruhan.
"China terus mengumumkan angka-angka pengeluaran pertahanan tidak lengkap, dan bertindak tidak konsisten dengan kebijakan yang dikeluarkan," menurut Laporan Tahunan Departemen Keamanan kepada Kongres pada "Kekuatan Militer RRC pada tahun 2008."
Sebuah dokumen dari Tentara Pembebasan Rakyat China (PLA) menyatakan bahwa "perang tidak hanya perjuangan militer, tetapi juga kontes komprehensif di bidang politik, ekonomi, diplomasi, dan hukum," menurut laporan Departemen Keamanan.
Itu menambahkan bahwa pada tahun 2003, Komite Sentral PKC menyetujui "Tiga Perang" yang mencakup perang psikologis melalui penggunaan propaganda, penipuan, ancaman, dan paksaan untuk mempengaruhi pemahaman musuh. Perang media bertujuan untuk mempengaruhi opini publik dan memperoleh dukungan domestik dan internasional, dan perang hukum menggunakan hukum internasional dan domestik untuk mendapatkan dukungan dan mengatur dampak akibat dari tindakan-tindakan militer rejim.
Cyberwarfare memiliki tempat yang kuat di keseluruhan strategi militer PKC dan "telah menjadi pilar strategi militer China sejak awal 1990-an," menurut laporan dari analis intelijen senior di SRA International Brian Mazanec.
PKC dikembangkan berdasarkan pada konsep bahwa perang masa depan tergantung pada mengganggu arus informasi musuh. "Jadi, pada manifesto 1999 mereka, Perang tak Terbatas, Kolonel Tentara Pembebasan Rakyat (PLA) Qiao Liang dan Wang Xiangsui mengusulkan bentuk peperangan yang 'melampaui semua bentuk dan batas-batas,' dan memanfaatkan peran sentral bahwa dunia maya berpengaruh dalam konflik di masa depan," kata Mazanec.
"Ancaman cyberwarfare dari RRC nyata dan berkembang. AS tidak bisa mengabaikan ancaman asimetris yang menjulang dari pesaing di Asia," menurut Mazanec.
ia menambahkan bahwa perang dunia maya PKC mampu "tidak hanya difokuskan pada pengumpulan informasi sensitif, tapi juga untuk mencapai efek militer mampu menyebabkan kerugian ekonomi, merusak infrastruktur vital dan mempengaruhi hasil dari konflik bersenjata konvensional." (EpochTimes/ray)
Perang Cyber Dimulai, Malaysia Deface Puluhan Situs Indonesia
Senin, 24 November 2008 - 11:17 wib
TEXT SIZE :
Sarie - Okezone
Jejak yang ditinggalkan Hacker Malaysia pada situs Indonesia
JAKARTA - Puluhan situs milik Indonesia berhasil disusupi hacker yang mengaku berasal dari Malaysia. Situs-situs asal Indonesia itu berhasil di deface dengan menyertakan gambar alien dan dua buah blog yang masing-masing dimiliki warga negara Malaysia dan warga negara Indonesia.
Saat ditelusuri okezone, Senin (24/11/2008), rupanya telah terjadi perseteruan antara hacker Indonesia dan Malaysia. Kedua hacker, yang masih-masing mengatasnamakan yadoyy666 (Indonesia) dan alien crew (Malaysia) saling unjuk kekuatan dengan melakukan aksi deface.
Akibatnya, puluhan situs Indonesia berhasil dideface oleh hacker asal Malaysia. Yang menjadi korban di antaranya situs Pemuda Hanura, Gerbang Linux, KBRI Beirut, FK Usakti 95, dan masih banyak lagi. Beberapa situs Malaysia pun mengalami aksi serupa akibat deface balasan dari hacker Indonesia.
Jika hacker Malaysia melakukan aksinya dengan menggunakan tema Hacked by Anti Indon, hacker Indonesia justru mengambil tema Ganyang Malingsial.
Jika terus berkelanjutan, hal ini akan memicu adanya perang cyber di dunia maya.(srn) (mbs)
JENAYAH siber dan pencabulan keselamatan Internet di Malaysia meningkat dalam lima tahun lalu dengan purata sebanyak 500 kes dilaporkan setiap tahun, kata Kementerian Tenaga, Komunikasi dan Multimedia baru-baru ini.
NSTP emedia/Berita Harian Online melaporkan timbalan menterinya, Datuk Tan Chai Ho, berkata dari Ogos 1997 hingga Julai 2002, Malaysia mengalami 3,050 kes terkumpul jenayah berkaitan Teknologi Maklumat dan Komunikasi (ICT).
Menurut beliau, bilangan kes yang dilaporkan sebanyak 503 pada tahun 2000 telah meningkat kepada 923 kes pada 2001, dengan sebanyak 14 individu telah disabitkan mengikut undang-undang siber pada 2000 dan 10 pada tahun lalu.
Katanya lagi, antara Ogos hingga Disember 1997, sebanyak 115 kes dilaporkan terdiri daripada pemalsuan komputer, serangan virus, gangguan, pencerobohan, pemusnahan melalui mel, mel tidak diundang dan ancaman pencerobohan komputer.
Pada 1998, terdapat 342 kes, 1999 (728 kes), 2000 (503 kes), 2001 (932 kes) dan bagi enam bulan pertama tahun ini, angkanya berjumlah 430 kes.
From the name of the network itself many inferences of the network can be derived. A bus topology in more technical terms means that it is a method of transmission on networks that uses a common vehicle for transmissions and thus it is categorized as shared communication. Imagine a bus picking up various people from one stop and dropping of people as it travels and then picking a few more. That is what happens in a bus network exactly.
Sponsored Links
However in a Bus topology only one device is allowed to transmit at a given point of time. The DAP or the Distribute Access Protocol has the information about which station has to transmit the data. The data that is being transmitted have frames that will have the source name and the network address.
Bus Topology Functionality
The bus topology connects each computer on the network into something called the segment trunk. A bus is usually referred to a cable that connects end to end and this is used to transmit the signals from one end to the other end. At every end a terminator is placed so that it understands in which direction the data is traveling and also the terminator is used to absorb the signals. If the terminator does not absorb the signal then the same signal is reflected back to the bus confusing the whole data flow. The bus is considered to be a passive network because the computers are largely dependant on the signal that is being transmitted.
Bus Topology Advantages
The advantage of the Bus network is that if one computer fails in the network the others are still not affected and they continue to work. Bus network is very simple and easy to set up. If there is an urgent need to set up a network and perhaps be used on a short term basis then the Bus network is the best possibility. Bus networks use the least amount of cable to set up making it cost effective.
Bus Topology Limitations
In the bus network you will need a network connection in order to determine if the data is being transferred between two nodes. If the data transfer rate is high then the Bus network does not perform very well because the data travels in a stream and cannot be overloaded. The bus network is a bit challenging when you have to troubleshoot the problems. Bus networks are not suitable as large networks as there are limitations to the number of nodes you can set up for one single cable. As the number of computers increase in the network the data transfer rate goes down accordingly and noticeably.
Bus Topology Conclusion
The bus networks in spite of its limitations is considered to be the easiest and the fastest network that can be set up compared to the other kinds of network. In bus networks there is a collision handling system which ensures that data travels without errors and data is delivered correctly.
Sponsored Links
There is a bus master on the network which ensures that data is flowing in the right direction and order. All the computers on the bus network however listen for the signals and they do not hold the responsibility to move the signal forward. The signal carries forward on its own. So if one computer is not receiving any signals the signal still carries forward without stopping at the computer that has failed. These days bus networks are less common due to the advancement of networks and there are much lesser complicated networks that are easy to operate and efficient. However even these newer technologies derive their basics from older technologies like the Bus Topology.
ring network is a network topology in which each node connects to exactly two other nodes, forming a single continuous pathway for signals through each node - a ring. Data travels from node to node, with each node along the way handling every packet.
Because a ring topology provides only one pathway between any two nodes, ring networks may be disrupted by the failure of a single link[1]. A node failure or cable break might isolate every node attached to the ring. FDDI networks overcome this vulnerability by sending data on a clockwise and a counterclockwise ring: in the event of a break data is wrapped back onto the complementary ring before it reaches the end of the cable, maintaining a path to every node along the resulting "C-Ring". 802.5 networks -- also known as IBM Token Ring networks -- avoid the weakness of a ring topology altogether: they actually use a star topology at the physical layer and a Multistation Access Unit (MAU) to imitate a ring at the datalink layer.
Very orderly network where every device has access to the token and the opportunity to transmit
Performs better than a bus topology under heavy network load
Does not require network server to manage the connectivity between the computers
Disadvantages
One malfunctioning workstation or bad port in the MAU can create problems for the entire network
Moves, adds and changes of devices can affect the network
Network adapter cards and MAU's are much more expensive than Ethernet cards and hubs
Much slower than an Ethernet network under normal load
Misconceptions
"Token Ring is an example of a ring topology." 802.5 (Token Ring) networks do not use a ring topology at layer 1. As explained above, IBM Token Ring (802.5) networks imitate a ring at layer 2 but use a physical star at layer 1.
"Rings prevent collisions." The term "ring" only refers to the layout of the cables. It is true that there are no collisions on an IBM Token Ring, but this is because of the layer 2 Media Access Control method, not the physical topology (which again is a star, not a ring.) Token passing, not rings, prevent collisions.
"Token passing happens on rings." Token passing is a way of managing access to the cable, implemented at the MAC sublayer of layer 2. Ring topology is the cable layout at layer one. It is possible to do token passing on a bus (802.4) a star (802.5) or a ring (FDDI). Token passing is not restricted to rings.
(Originally published in EDN Magazine, November 11, 2004)
A star topology connects N devices in a completely symmetrical, peer-to-peer fashion. Each device in the star connects to a central node where all the wires directly join together. The star topology looks like a great way to interconnect a collection of remote devices, but a big problem exists.
Every signal arriving at the central hub encounters the other N–1 wires all connected together in parallel. Assuming all wires have the same characteristic impedance, Z0, the apparent load impedance of the hub equals Z0/(N–1), producing a reflection coefficient of (N–2)/N. Large values of N produce large reflections that wreak havoc on your signal quality.
A small star might work satisfactorily if the reflections settle quickly. However, you will never achieve first-incident wave switching with full-amplitude received signals if the connecting wires, and, thus, the signal-propagation times, are long compared with the rise or fall time of your signals (Reference 1).
You can, however, obtain excellent signal quality if you permit a certain degree of signal attenuation. As a general rule, you can always insert damping into any old hairball network to stop the reflections but at the cost of a diminished received amplitude. If you are using LVDS (low-voltage-differential-signaling) logic, then the diminished amplitude may not hurt you. LVDS logic, like many other differential-logic families, is built to handle plenty of signal attenuation.
Figure 1illustrates a single-ended attenuating network that you can use with a star topology. The figure assumes that all of the inactive endpoints end-terminate with impedance Z0. A differential network uses the same circuit, just replicated for the other element of the differential pair.
For the case N=3, set R1 equal to Z0/3. That solution produces no reflections, making the entire hub electrically transparent except for a fixed gain of ½. In essence, the circuit trades half of your signal amplitude to eliminate a major source of reflections. In general, a star having N devices requires R1=Z0(N–2)/N and produces a gain of 1/(N–1).
For the special case of N=3, you may transform the network of Figure 1into a delta configuration having a resistor with value Z0 spanning between each pair of signal inputs.
In all cases, the entire network of resistors at the central hub must remain physically small compared with the rise time of your signals, so that the resistor network behaves in an ideal lumped-element fashion.
If you unplug one device from the star, you can no longer depend on that device's termination to maintain a stable impedance at the hub. For example, in a hub designed for N=3, disconnecting one device changes the impedance of the hub by roughly one part in three. The only way to stabilize the impedance of the hub in this system is to add even more attenuation to your coupling network. To accomplish this feat, you could design the R1 resistor values in Figure 1for, say, N=10, but then install only a maximum of three devices. In this case, you must install a fixed resistor, R2=(R1+Z0)/7, to model the effect of the seven missing devices. Removing one device now affects the circuit by only one part in 10.
Until a couple of years ago there were not that many people who were acquainted with the end of the world 2012 prophecy that was put forward by many scholars who studied the end of the Mayan long calendar. This Long Count calendar has lasted for five thousand one hundred and twenty five years, and although the end of the calendar leads to many different interpretations, one of the most popular is the belief that at the end of this cycle the world (or humanity’s existence) will come to an abrupt end on December 21 2012.
