3_WuL4N

2010-06-18T09:34:00.000-07:00

Nama : Tri Wulandari
NPM : 50406724
Kelas : 4IA13
Greedy Algorithm
A greedy algorithm is any algorithm that follows the problem solving metaheuristic of making the locally optimal choice at each stage with the hope of finding the global optimum.
For example, applying the greedy strategy to the traveling salesman problem yields the following algorithm: "At each stage visit the unvisited city nearest to the current city".
Specifics
In general, greedy algorithms have five pillars:
1. A candidate set, from which a solution is created
2. A selection function, which chooses the best candidate to be added to the solution
3. A feasibility function, that is used to determine if a candidate can be used to contribute to a solution
4. An objective function, which assigns a value to a solution, or a partial solution, and
5. A solution function, which will indicate when we have discovered a complete solution
Greedy algorithms produce good solutions on some mathematical problems, but not on others. Most problems for which they work well have two properties:
Greedy choice property
We can make whatever choice seems best at the moment and then solve the subproblems that arise later. The choice made by a greedy algorithm may depend on choices made so far but not on future choices or all the solutions to the subproblem. It iteratively makes one greedy choice after another, reducing each given problem into a smaller one. In other words, a greedy algorithm never reconsiders its choices. This is the main difference from dynamic programming, which is exhaustive and is guaranteed to find the solution. After every stage, dynamic programming makes decisions based on all the decisions made in the previous stage, and may reconsider the previous stage's algorithmic path to solution.

Optimal substructure
"A problem exhibits optimal substructure if an optimal solution to the problem contains optimal solutions to the sub-problems." Said differently, a problem has optimal substructure if the best next move always leads to the optimal solution. An example of 'non-optimal substructure' would be a situation where capturing a queen in chess (good next move) will eventually lead to the loss of the game (bad overall move).

When greedy-type algorithms fail
For many other problems, greedy algorithms fail to produce the optimal solution, and may even produce the unique worst possible solutions. One example is the nearest neighbor algorithm mentioned above: for each number of cities there is an assignment of distances between the cities for which the nearest neighbor heuristic produces the unique worst possible tour.
Imagine the coin example with only 25-cent, 10-cent, and 4-cent coins. The greedy algorithm would not be able to make change for 41 cents, since after committing to use one 25-cent coin and one 10-cent coin it would be impossible to use 4-cent coins for the balance of 6 cents. Whereas a person or a more sophisticated algorithm could make change for 41 cents change with one 25-cent coin and four 4-cent coins.
Types
Greedy algorithms can be characterized as being 'short sighted', and as 'non-recoverable'. They are ideal only for problems which have 'optimal substructure'. Despite this, greedy algorithms are best suited for simple problems (e.g. giving change). It is important, however, to note that the greedy algorithm can be used as a selection algorithm to prioritize options within a search, or branch and bound algorithm. There are a few variations to the greedy algorithm:
• Pure greedy algorithms
• Orthogonal greedy algorithms
• Relaxed greedy algorithms
Applications
Greedy algorithms mostly (but not always) fail to find the globally optimal solution, because they usually do not operate exhaustively on all the data. They can make commitments to certain choices too early which prevent them from finding the best overall solution later. For example, all known greedy coloring algorithms for the graph coloring problem and all other NP-complete problems do not consistently find optimum solutions. Nevertheless, they are useful because they are quick to think up and often give good approximations to the optimum.
If a greedy algorithm can be proven to yield the global optimum for a given problem class, it typically becomes the method of choice because it is faster than other optimisation methods like dynamic programming. Examples of such greedy algorithms are Kruskal's algorithm and Prim's algorithm for finding minimum spanning trees, Dijkstra's algorithm for finding single-source shortest paths, and the algorithm for finding optimum Huffman trees.
The theory of matroids, and the more general theory of greedoids, provide whole classes of such algorithms.
Greedy algorithms appear in network routing as well. Using greedy routing, a message is forwarded to the neighboring node which is "closest" to the destination. The notion of a node's location (and hence "closeness") may be determined by its physical location, as in geographic routing used by ad-hoc networks. Location may also be an entirely artificial construct as in small world routing and distributed hash table.

PEMBAHASAN :
Algoritma greedy adalah algoritma yang memecahkan masalah langkah demi langkah. Pada setiap langkah, yaitu mengambil pilihan yang terbaik yang dapat diperoleh saat itu dan berharap bahwa dengan memilih optimum lokal pada setiap langkah akan mencapai optimum global. Algoritma greedy mengasumsikan bahwa optimum lokal merupakan bagian dari optimum global. Persoalan optimasi dalam algoritma greedy disusun oleh elemen-elemen sebagai berikut:
1. Himpunan kandidat. Himpunan ini berisi elemen-elemen pembentuk solusi. Pada setiap langkah, satu buah kandidat diambil dari himpunannya.
2. Himpunan solusi. Himpunan dari kandidat-kandidat yang terpilih sebagai solusi persoalan. Himpunan solusi adalah himpunan bagian dari himpunan kandidat.
3. Fungsi seleksi – dinyatakan sebagai predikat dan merupakan fungsi yang pada setiap langkah memilih kandidat yang paling mungkin untuk mendapatkan solusi optimal. Kandidat yang sudah dipilih pada suatu langkah tidak pernah dipertimbangkan lagi pada langkah selanjutnya.
4. Fungsi kelayakan (feasible) – dinyatakan dengan predikat LAYAK dan merupakan fungsi yang memeriksa apakah suatu kandidat yang telah dipilih dapat memberikan solusi yang layak.
5. Fungsi obyektif, merupakan fungsi yang memaksimumkan atau meminimumkan nilai solusi.

PEMROGRAMAN MULTIMEDIA

2010-03-03T08:34:00.000-08:00

Literatur tentang Pemrograman Multimedia adalah sebagai berikut :

1. Sumber berupa Textbook

URL :

* http://books.google.co.id/books?id=3uAMIBpFfoUC&pg=PA103&dq=pemrograman+multimedia&cd=1#v=onepage&q=pemrograman%20multimedia&f=false

Judul Buku : Multimedia Alat Untuk Meningkatkan Keunggulan Bersaing

Penulis : M.Suyanto (Amikom, Yogyakarta)

* http://elista.akprind.ac.id/staff/catur/Sistem%20Multimedia/11-Distribusi%20Multimedia.pdf

2. Sumber berupa slide presentasi

URL :

* http://www.akademik.unsri.ac.id/download/journal/files/gdr/GUI%20&%20Multimedia.ppt
* www.e-dukasi.net/sosialisasi/files/Multimedia/Multimedia.ppt

3. Sumber berupa artikel di jurnal / proseding

URL :

* http://v3.juhara.com/id/artikel/pemrograman-multimedia
* http://rosni-gj.staff.gunadarma.ac.id/Downloads/files/9629/multimedia+def.doc
* http://id.wikipedia.org/wiki/Multimedia
* http://www.masaguz.com/search/Jurnal+UI
* http://jurnal.bl.ac.id/?p=286
* http://jurnaliqro.wordpress.com/2008/08/12/pengembangan-multimedia-pembelajaran-berbantuan-komputer/

4. Contoh Kasus dan Solusi tentang Pemrograman Multimedia

Masalah Media Player

Anda mungkin mempunyai koleksi musik dan video yang luar bisa banyak mungkin hingga ratusan atau ribuan gigabytes akan tetapi dengan semakin banyaknya file yang Anda miliki mungkin akan sangat merepotkan tanpa adanya Software yang dapat memudahkan penanganan file AudioVideo yang Anda miliki.

Solusi

Berikut ini adalah 5 Aplikasi MediaPlayer yang akan dapat membantu Anda dalam memanajemen file AudioVideo yang Anda miliki.

Foobar2000, Anda dapat melakukan berbagai macam perubahan pada file AudioVideo yang Anda miliki, foobar2000 mempunyai plug-ins seperti iPod support, album art, lyrics, media portable.

Winamp, Sudah banyak orang yang sudah ketahui mengenai MediaPlayer yang satu ini sangat mudah digunakan dan sangat populer dalam penanganan file AudioVidio.

iTunes, Aplikasi MediaPlayer yang sangat populer yang digunakan untuk manajemen file AudioVideo pada iPod.

Amarok, MediaPlayer yang sangat terkenal digunakan pada SistemOperasi Linux dalam memanajemen file AudioVideo dan mendukung automatic album art imports, lyrics support, dan Wikipedia integration.

VLC, adalah Aplikasi MediaPlayer yang dapat digunakan dalam cross-platform seperti layaknya Swiss Army knife dalam menangani file AudioVideo.

Contoh Surat Lamaran

2009-11-18T06:39:00.000-08:00

Jl. Raya Cakung 01
Jakarta

Phone : 021 -4610082

August 17th, 2009

Attention To:
Mr. Joko
PT. Damai Indonesia
Jl. Sudirman
jakarta

Dear Mr. Joko,

I am a graduate student in Computer Science at Indonesia University, and I will be awarded an M.S. degree in July 2007. I am currently looking for a position related to Database/Graphics Package Design in the research and development department of a major company.

Before coming to Indonesia University, I designed, supervised, and completed a CAD system. The function covers vector, character and curve generation, windowing, shading, and transformations.

At Indonesia University, my research work involves Compilation of Relational Queries into Network DML. To enhance my background, I have taken some courses in computer graphics and database, and I have experience in and an understanding of the design of databases. With this b background, I certainly believe that I am competent to meet challenging tasks and can make a good contribution to your company.

Enclosed is my resume, which indicates in some detail my training and experience. I sincerely hope that my qualifications are of interest to you and that an interview might be arranged at your convenience.

Thank you for your consideration. I look forward to hearing from you soon.

Sincerely yours,

Wulan

FDM,TDM dan CDM

2009-11-11T07:30:00.000-08:00

FDM, TDM dan CDM

Tiga teknik multiplexing :

 Frequency-Division Multiplexing (FDM), paling umum dipakai untuk radio atau TV
 Time-Division Multiplexing (TDM) atau synchronous TDM, dipakai untuk multiplexing digital voice dan banyak digunakan untuk menggabungkan aliran suara digital dan aliran data
 Peningkatan efisiensi Synchronous TDM dengan variasi sebagai berikut :
o Statistical TDM atau
o Asynchronous TDM atau
o Intelligent TDM
Bertujuan memperbaiki efisiensi synchronous TDM dengan cara menambahkan rangkaian yang lebih kompleks di sisi multiplexer

Frequency Division Multiplexing (FDM)

Tiap sinyal dimodulasikan ke dalam frekuensi carrier yang berbeda dan frekuensi carrier tersebut terpisah dimana bandwidth dari sinyal-sinyal tersebut tidak overlap.

 FDM dimungkinkan jika bandwidth media transmisi jauh lebih besar daripada required BW sinyal yang akan dikirim.
Contoh: sistem siaran televisi, CATV, AMPS analog

Time-Division Multiplexing TDM

Time-Division Multiplexing (TDM) adalah suatu jenis digital yang terdiri dari banyak bagian di mana teradapat dua atau lebih saluran yang sama diperoleh dari spektrum frekwensi yang diberikan yaitu, bit arus, atau dengan menyisipkan detakan-detakan yang mewakili bit dari saluran berbeda. Dalam beberapa TDM sistem, detakan yang berurutan menghadirkan bit dari saluran yang berurutan seperti saluran suara pada sistem T1. Pada sistem yang lainnya saluran-saluran yang berbeda secara bergiliran menggunakan saluran itu dengan membuat sebuah kelompok yang berdasarkan pada pulse-times (hal seperti ini disebut dengan time slot). Apakah yang menjadi ciri dari TDM yang tidak beraturan (kasar), adalah belum ditempatkannya time slot pada saluran-saluran ( channels ) yang telah ditentukan.

Contoh penggunaan TDM

* PDH dan SDH transmisi jaringan baku
* GSM pada sistem telepon
* Saluran kiri-kanan pada sebuah kacamata yang menggunakan cairan Stereoskopis Crystle

TDM adalah rata-rata dari sinyal digital (sinyal analog yang membawa data digital) yang dapat dilaksanakan denga alur transmisi tunggal dengan menyisipkan antar halaman bagian dari tiap sinyal pada waktunya. Penyisipkan dapat dilakukan pada bit atau blok bytes. Ini memungkinkan secara digital menyandi sinyal suara untuk dipancarkan dan diganti secara optimal dengan saklar sirkuit yang ada dalam sebuah jaringan. Artikel ini terdiri dari dua bagian yaitu Transmisi yang menggunakan TDM dan Synchronous Hirarki Digital ( SDH). Bagian yang pertama menguji prinsip dasar yang mendasari TDM, sedangkan bagian yang kedua mendiskusikan bagaimana SDH digunakan untuk mengganti tampilan TDM.

Transmisi menggunakan TDM

Di dalam sebuah sirkuit saklar untuk jaringan seperti pada jaringan telepon umum terdapat sebuah kebutuhan untuk memancarkan berbagai panggilan langganan sepanjang medium transmisi yang sama. Untuk memenuhi ini, para perancang jaringan menggunakan TDM. TDM menyertakan tombol (saklar) untuk menciptakan saluran (channel) yang dikenal sebagai anak sungai di dalam suatu arus transmisi. Sebuah sinyal standar suara mempunyai suatu luas bidang 64 kbit/s, yang ditentukan menggunakan Ukuran Sampling Nyquist'S. Jadi, jika layar (bingkai) TDM terdiri dari n (beberapa) layar (bingkai/frame) luas bidangnya atau bandwith-nya sebesar 64 Kbits/s.

Masing-masing suara dalam TDM disebut suatu saluran (channel) atau anak sungai. Di dalam sistem benua Eropa, TDM berisi 30 suara digital dan di dalam sistem Amerika, TDM berisi 24 suara digital. Kedua standar juga berisi ruang ekstra untuk memberi sinyal dan sinkhronisasi data.

TDM yang lebih dari 24 atau 30 suara digital disebut Higher Order Multiplexing (HOM).HOM terpunuhi atas standar dari TDM. Sebagai contoh, 120 saluran TDM milik benua Eropa dibentuk dengan terdiri dari empat standar baku yang terdiri dari 30 saluran TDM setiap standar bakunya. Pada masing-masing HOM, 4 TDM dari urutan yang lebih rendah dikombinasikan. Sebuah sinyal standar suara mempunyai suatu luas bidang n x 64 kbit/s, di mana n = 120, 480, 1920

Code Division Multiplexing (CDM)

1.PENJELASAN
Code Division Multiplexing (CDM) dirancang untuk menanggulangi kelemahankelemahan yang dimiliki oleh teknik multiplexing sebelumnya, yakni TDM dan FDM.. Contoh aplikasinya pada saat ini adalah jaringan komunikasi seluler CDMA (Flexi)

2.PRINSIP KERJA
1.Kepada setiap entitas pengguna diberikan suatu kode unik (dengan panjang 64 bit) yang disebut chip spreading code.
2.Untuk pengiriman bit ‘1’, digunakan representasi kode (chip spreading code) tersebut.
3.Sedangkan untuk pengiriman bit ‘0’, yang digunakan adalah inverse dari kode tersebut.
4.Pada saluran transmisi, kode-kode unik yang dikirim oleh sejumlah pengguna akan ditransmisikan dalam bentuk hasil penjumlahan (sum) dari kode-kode tersebut.
5.Di sisi penerima, sinyal hasil penjumlahan kode-kode tersebut akan dikalikan dengan kode unik dari si pengirim (chip spreading code) untuk diinterpretasikan selanjutnya :
•jika jumlah hasil perkalian mendekati nilai +64 berarti bit ‘1’,
•jika jumlahnya mendekati –64 dinyatakan sebagai bit ‘0’.

X.25

2009-11-11T07:28:00.000-08:00

X.25 adalah packet switched data network protocol yang mendefinisikan secara internasional bagaimana cara melakukan data exchange dan information control antara user device (host), disebut Data Terminal Equipment (DTE) dan network node, disebut Data Circuit Terminating Equipment (DCE). atau X.25 adalah Connection Oriented service yang memastikan paket ditransmisikan berurutan.

X.25 mengacu pada tiga layer pertama Open Systems Interconnection(OSI) dalam arsitektur 7 Later yang ditetapkan oleh International Standard Organization (ISO).

1. Physical Level adalah interface secara fisik. Sesuai dengan Physical Layer pada OSI model
2. The Link Level bertanggung jawab terhadap komunikasi antara DTE dan DCE. Sesuai dengan Data Link Layer pada OSI model
3. The Packet Level mendeskripsikan data transfer protocol pada packet switched network. Sesuai dengan Network Layer pada OSI model.

X.25 disetujui pada 1976 dan direvisi pada 1977, 1980, 1984, 1988 and 1992. Saat ini digunakan sebagai interfaces data communication networks terluas di seluruh dunia.

X.25 adalah protocol yang mendefinisikan bagaimana computer (device) pada jaringan public yang berbeda platform bisa saling berkomunikasi. Protocol yang sudah distandarisasi oleh International Telecommunication Union-Telecommunication Standardization Sector (ITU-T).

Device pada X.25 ini terbagi menjadi tiga kategori:

* Data Terminal Equipment (DTE),
* Data Circuit-terminating Equipment (DCE) serta
* Packet Switching Exchange (PSE).

* Device yang digolongkan DTE adalah end-system seperti terminal, PC, host jaringan (user device).
* Sedang device DCE adalah device komunikasi seperti modem dan switch. Device inilah yang menyediakan interface bagi komunikasi antara DTE dan PSE. Adapun PSE ialah switch yang yang menyusun sebagian besar carrier network. Hubungan antar ketiga kategori ini diilustrasikan pada gambar 2.

Protokol Pada X.25

Penggunaan protokol pada model standar X.25 ini meliputi tiga layer terbawah dari model referensi OSI. Terdapat tiga protokol yang biasa digunakan pada implementasi X.25 yaitu:

* Packet-Layer Protocol (PLP),
* Link Access Procedure, Balanced (LAPB)
* Serta beberapa standar elektronik dari interface layer fisik seperti EIA/TIA-232, EIA/TIA-449, EIA-530, dan G.703.

Lapisan-lapisan X25

Layer 1:

* Physical Layer bekerja dengan elektris atau sinyal. Didalamnya termasuk beberapa standar elektronik seperti is V.35 , RS232 and X.21.

Layer 2:

* Data Link Layer, pada X.25 diimplementasikan ISO HDLC standar yang disebut Link Access Procedure Balanced (LAPB) dan menyediakan link yang bebas error antara dua node yang secara fisik terkoneksi. Error ini akan dicek dan dikoreksi pada tiap hop pada network.
* Fasilitas inilah yang membuat X.25 handal, dan cocok untuk link yang noisy, cenderung punya banyak error.
* Protocol modern seperti Frame Relay atau ATM tidak punya error correction dan hanya memiliki basic flow control. Mereka merngandalkan protokol pada level yang lebih tinggi seperti TCP/IP untuk menyediakan flow control dan end-to-end error correction.

Layer 3:

* Network Layer yang mengatur komunikasi end-to-end antar device DTE. Layer ini mengurus set-up dan memutus koneksi serta fungsi routing dan juga multiplexing.

Implementasi X.25

* Contoh cara mengkonfigurasi X.25 dengan perintah encapsulation pada cisco router:
* Router(config)#int s0
* Router(config-if)#encap x25
* Router(config-if)#x25

adddress dengan metode X.121
* Router(config-if)#x25 ips <16-4096> ips adalah input packet size
* Router(config-if)#x25 win <1-127> win adalah window size
* Beberapa perintah yang dapat digunakan untuk memeriksa konfigurasi X.25 antara lain:
* Router#show x.25 map menampilkan peta alamat x.25
* Router#show x.25 route menampilkan tabel routing x.25
* Router#show x.25 vc menampilkan daftar SVC dan PVC aktif
* Router#show x.25 remote-red tampil mapping lokal&remote IPaddress

Frame Relay

2009-11-11T07:22:00.000-08:00

Frame Relay adalah protokol WAN yang beroperasi pada layer pertama dan kedua dari model OSI, dan dapat diimplementasikan pada beberapa jenis interface jaringan. Frame relay adalah teknologi komunikasi berkecepatan tinggi yang telah digunakan pada ribuan jaringan di seluruh dunia untuk menghubungkan LAN, SNA, Internet dan bahkan aplikasi suara/voice.

Frame relay adalah cara mengirimkan informasi melalui wide area network (WAN) yang membagi informasi menjadi frame atau paket. Masing-masing frame mempunyai alamat yang digunakan oleh jaringan untuk menentukan tujuan. Frame-frame akan melewati switch dalam jaringan frame relay dan dikirimkan melalui â€œvirtual circuitâ€ sampai tujuan.

Fitur Frame Relay

Beberapa fitur frame relay adalah sebagai berikut:

1. Kecepatan tinggi
2. Bandwidth Dinamik
3. Performansi yang baik/ Good Performance
4. Overhead yang rendah dan kehandalah tinggi (High Reliability)

Perangkat Frame Relay

Sebuah jaringan frame relay terdiri dari endpoint (PC, server, komputer host), perangkat akses frame relay (bridge, router, host, frame relay access device/FRAD) dan perangkat jaringan (packet switch, router, multiplexer T1/E1). Perangkat-perangkat tersebut dibagi menjadi dua kategori yang berbeda:
* DTE: Data Terminating Equipment

DTE adalah node, biasanya milik end-user dan perangkat internetworking. Perangkat DTE ini mencakup endpoint dan perangkat akses pada jaringan Frame Relay. DTE yang memulai suatu pertukaran informasi.

* DCE: Data Communication Equipment

DCE adalah perangkat internetworking pengontrol carrier. Perangkat-perangkat ini juga mencakup perangkat akses, teatpi terpusat di sekitar perangkat jaringan. DCE merespon pertukaran informasi yang dimulai oleh perangkat DTE.
Pendeteksi Error pada Frame Relay

Frame Relay menerapkan pendeteksi error pada saluran transmisi, tetapi Frame Relay tidak memperbaiki error. Jika terdeteksi sebuah error, frame akan dibuang (discarded) dari saluran transmisi. Proses seperti ini disebut :

Cyclic redundancy check (CRC)

Cyclic redundancy check (CRC) adalah sebuah skema error-checking yang mendeteksi dan membuang data yang rusak (corrupted). Fungsi yang memperbaiki error (Error-correction) (seperti pengiriman kembali/retransmission data) diserahkan pada protokol layer yang lebih tinggi (higher-layer).

Implementasi Frame Relay

Frame Relay dapat digunakan untuk jaringan publik dan jaringan private perusahaan atau organisasi.

Jaringan Publik

Pada jaringan publik Frame Relay, Frame Relay switching equipment (DCE) berlokasi di kantor pusat (central) perusahaan penyedia jaringan telekomunikasi. Pelanggan hanya membayar biaya berdasarkan pemakain jaringan, dan tidak dibebani administrasi dan pemeliharan perangkat jaringan Frame Relay.

Jaringan Private

Pada jaringan private Frame Relay, administrasi dan pemeliharaan jaringan adalah tanggungjawab perusahaan (private company). Trafik Frame Relay diteruskan melalui interface Frame Relay pada jaringan data. Trafik Non-Frame Relay diteruskan ke jasa atau aplikasi yang sesuai (seperti private branch exchange [PBX] untuk jasa telepon atau untuk aplikasi video-teleconferencing).

Security System

2009-10-21T09:04:00.000-07:00

Security system adalah suatu system atau mekanisme yang dirancang sedemikian rupa yang digunakan untuk mengamankan sebuah perangkat hardware atau software pada sebuah computer.

Faktor keamanan informasi dengan menggunakan teknologi. Hal tersebut disebabkan karena adanya kelemahan-kelemahan di dalam:
- kebijaksanaan jaringan suatu perusahaan (Policy Vulnerabilities),
- konfigurasi suatu sistem (Configuration Vulnerabilities)
- teknologi yang digunakan (Technology Vulnerabilities).

Kelemahan-kelemahan itu biasanya dimanfaatkan untuk menyusup ke dalam suatu jaringan komputer tanpa diketahui pengelolanya. Beberapa masalah yang bisa timbul antara lain adalah:
- Packet Sniffing,
- Identity Spoofing,
- Data Theft,
- Data Alteration.

Selain hal tersebut di atas, masih banyak lagi masalah-masalah yang dapat timbul dari lemahnya sekuriti suatu jaringan. Ping-of-Death adalah salah satu cara untuk membuat suatu sistem menjadi crash, dengan mengirimkan ping dari suatu remote machine.

Untuk mengatasi hal-hal tersebut di atas, maka dibutuhkan solusi-solusi yang tepat dalam pengimplementasian teknologi jaringan. Jalur komunikasi yang akan dipakai harus benar-benar terjamin keamanan dan kehandalannya.

Diantara solusi untuk menyelesaikan permasalahan security ini adalah melalui:
1. Tunneling protocol,
2. IPSec : Merupakan implementasi IPv6 (IP version 6) security protocol (yang tercantum dalam RFC 1825 sampai dengan 1829) akan tetapi teknologi ini juga dapat digunakan dengan IPv4 (IP version 4).
3. Identification process.

DETERMINERS

2009-10-14T08:13:00.000-07:00

Articles, Determiners,
and Quantifiers

Definition

Articles, determiners, and quantifiers are those little words that precede and modify nouns:

the teacher, a college, a bit of honey, that person, those people, whatever purpose, either way, your choice

Sometimes these words will tell the reader or listener whether we're referring to a specific or general thing (the garage out back; A horse! A horse! My kingdom for a horse!); sometimes they tell how much or how many (lots of trees, several books, a great deal of confusion). The choice of the proper article or determiner to precede a noun or noun phrase is usually not a problem for writers who have grown up speaking English, nor is it a serious problem for non-native writers whose first language is a romance language such as Spanish. For other writers, though, this can be a considerable obstacle on the way to their mastery of English. In fact, some students from eastern European countries — where their native language has either no articles or an altogether different system of choosing articles and determiners — find that these "little words" can create problems long after every other aspect of English has been mastered.

Determiners are said to "mark" nouns. That is to say, you know a determiner will be followed by a noun. Some categories of determiners are limited (there are only three articles, a handful of possessive pronouns, etc.), but the possessive nouns are as limitless as nouns themselves. This limited nature of most determiner categories, however, explains why determiners are grouped apart from adjectives even though both serve a modifying function. We can imagine that the language will never tire of inventing new adjectives; the determiners (except for those possessive nouns), on the other hand, are well established, and this class of words is not going to grow in number. These categories of determiners are as follows: the articles (an, a, the — see below; possessive nouns (Joe's, the priest's, my mother's); possessive pronouns, (his, your, their, whose, etc.); numbers (one, two, etc.); indefinite pronouns (few, more, each, every, either, all, both, some, any, etc.); and demonstrative pronouns. The demonstratives (this, that, these, those, such) are discussed in the section on Demonstrative Pronouns. Notice that the possessive nouns differ from the other determiners in that they, themselves, are often accompanied by other determiners: "my mother's rug," "the priests's collar," "a dog's life."

This categorization of determiners is based on Understanding English Grammar by Martha Kolln. 4rth Edition. MacMillan Publishing Company: New York. 1994.

Some Notes on Quantifiers

Like articles, quantifiers are words that precede and modify nouns. They tell us how many or how much. Selecting the correct quantifier depends on your understanding the distinction between Count and Non-Count Nouns. For our purposes, we will choose the count noun trees and the non-count noun dancing:

The following quantifiers will work with count nouns:
many trees
a few trees
few trees
several trees
a couple of trees
none of the trees

The following quantifiers will work with non-count nouns:
not much dancing
a little dancing
little dancing
a bit of dancing
a good deal of dancing
a great deal of dancing
no dancing

The following quantifiers will work with both count and non-count nouns:
all of the trees/dancing
some trees/dancing
most of the trees/dancing
enough trees/dancing
a lot of trees/dancing
lots of trees/dancing
plenty of trees/dancing
a lack of trees/dancing

In formal academic writing, it is usually better to use many and much rather than phrases such as a lot of, lots of and plenty of.

There is an important difference between "a little" and "little" (used with non-count words) and between "a few" and "few" (used with count words). If I say that Tashonda has a little experience in management that means that although Tashonda is no great expert she does have some experience and that experience might well be enough for our purposes. If I say that Tashonda has little experience in management that means that she doesn't have enough experience. If I say that Charlie owns a few books on Latin American literature that means that he has some some books — not a lot of books, but probably enough for our purposes. If I say that Charlie owns few books on Latin American literature, that means he doesn't have enough for our purposes and we'd better go to the library.

Unless it is combined with of, the quantifier "much" is reserved for questions and negative statements:

Much of the snow has already melted.
How much snow fell yesterday?
Not much.

Note that the quantifier "most of the" must include the definite article the when it modifies a specific noun, whether it's a count or a non-count noun: "most of the instructors at this college have a doctorate"; "most of the water has evaporated." With a general plural noun, however (when you are not referring to a specific entity), the "of the" is dropped:

Most colleges have their own admissions policy.
Most students apply to several colleges.

An indefinite article is sometimes used in conjunction with the quantifier many, thus joining a plural quantifier with a singular noun (which then takes a singular verb):

Many a young man has fallen in love with her golden hair.
Many an apple has fallen by October.

	Countable Nouns	Uncountable Nouns	-
much		x	I don't have much money.
many	x	-	I don't have many apples.
few*	x	-	We know few people in the area. I would like to get to know more.
a few**	x	-	We know a few people in the area. I know enough people to keep me happy.
little*	-	x	I know little English. I am going to have a problem getting around England.
a little**	-	x	I know a little English, at least enough to get England.
enough	x	x	I have enough money.
plenty	x	x	I have plenty of money.

** a few/a little - means that there are not a lot of something, but there is enough.

There are a few apples. There are enough apples.
There are a people at the meeting. There are enough people to hold a meeting. There are not a lot people, at the meeting, but there are enough
I know a little English. He know enough English to manage.
I have a little money.

*few/little - means that is not enough of something.

There are few apples. There are not enough apples.
There are few people. There are not enough people at the meeting. We can't hold a meeting, because there are not enough people.
There is little money. We can't buy a lot of expensive food.
If things for the holiday. I don't have enough money, then we will stay home and have a great time.
They know little English. They can't get around very well. They don't know enough English to manage.

A / An / The

2009-10-14T08:10:00.000-07:00

Using Articles

What is an article? Basically, an article is an adjective. Like adjectives, articles modify nouns. English has two articles: the and a/an. The is used to refer to specific or particular nouns; a/an is used to modify non-specific or non-particular nouns. We call the the definite article and a/an the indefinite article.

the = definite article

a/an = indefinite article

For example, if I say, "Let's read the book," I mean a specific book. If I say, "Let's read a book," I mean any book rather than a specific book. Here's another way to explain it: The is used to refer to a specific or particular member of a group. For example, "I just saw the most popular movie of the year." There are many movies, but only one particular movie is the most popular. Therefore, we use the. "A/an" is used to refer to a non-specific or non-particular member of the group. For example, "I would like to go see a movie." Here, we're not talking about a specific movie. We're talking about any movie. There are many movies, and I want to see any movie. I don't have a specific one in mind. Let's look at each kind of article a little more closely.

Indefinite Articles: a and an

"A" and "an" signal that the noun modified is indefinite, referring to any member of a group. For example:

"My daughter really wants a dog for Christmas." This refers to any dog. We don't know which dog because we haven't found the dog yet.
"Somebody call a policeman!" This refers to any policeman. We don't need a specific policeman; we need any policeman who is available.
"When I was at the zoo, I saw an elephant!" Here, we're talking about a single, non-specific thing, in this case an elephant. There are probably several elephants at the zoo, but there's only one we're talking about here.

Remember, using a or an depends on the sound that begins the next word. So...

a + singular noun beginning with a consonant: a boy; a car; a bike; a zoo; a dog
an + singular noun beginning with a vowel: an elephant; an egg; an apple; an idiot; an orphan
a + singular noun beginning with a consonant sound: a user (sounds like 'yoo-zer,' i.e. begins with a consonant 'y' sound, so 'a' is used); a university; a unicycle
In some cases where "h" is pronounced, such as "historical," us an:

An historical event is worth recording.

In writing, "a historical event" is more commonly used.

Remember that this rule also applies when you use acronyms:

Introductory Composition at Purdue (ICaP) handles first-year writing at the University. Therefore, an ICaP memo generally discusses issues concerning English 106 instructors. Another case where this rule applies is when acronyms start with consonant letters but have vowel sounds:

An MSDS (material safety data sheet) was used to record the data. An SPCC plan (Spill Prevention Control and Countermeasures plan) will help us prepare for the worst. If the noun is modified by an adjective, the choice between a and an depends on the initial sound of the adjective that immediately follows the article:

a broken egg
an unusual problem
a European country (sounds like 'yer-o-pi-an,' i.e. begins with consonant 'y' sound)

Remember, too, that in English, the indefinite articles are used to indicate membership in a group:

I am a teacher. (I am a member of a large group known as teachers.)
Brian is an Irishman. (Brian is a member of the people known as Irish.)
Seiko is a practicing Buddhist. (Seiko is a member of the group of people known as Buddhists.)

Definite Article: the

The definite article is used before singular and plural nouns when the noun is specific or particular. The signals that the noun is definite, that it refers to a particular member of a group. For example:

"The dog that bit me ran away." Here, we're talking about a specific dog, the dog that bit me.

"I was happy to see the policeman who saved my cat!" Here, we're talking about a particular policeman. Even if we don't know the policeman's name, it's still a particular policeman because it is the one who saved the cat.

"I saw the elephant at the zoo." Here, we're talking about a specific noun. Probably there is only one elephant at the zoo.

Count and Noncount Nouns

The can be used with noncount nouns, or the article can be omitted entirely.

"I love to sail over the water" (some specific body of water) or "I love to sail over water" (any water).
"He spilled the milk all over the floor" (some specific milk, perhaps the milk you bought earlier that day) or "He spilled milk all over the floor" (any milk).

"A/an" can be used only with count nouns.

"I need a bottle of water."
"I need a new glass of milk."

Most of the time, you can't say, "She wants a water," unless you're implying, say, a bottle of water.

Geographical use of the

There are some specific rules for using the with geographical nouns. Do not use the before:

names of most countries/territories: Italy, Mexico, Bolivia; however, the Netherlands, the Dominican Republic, the Philippines, the United States
names of cities, towns, or states: Seoul, Manitoba, Miami
names of streets: Washington Blvd., Main St.
names of lakes and bays: Lake Titicaca, Lake Erie except with a group of lakes like the Great Lakes
names of mountains: Mount Everest, Mount Fuji except with ranges of mountains like the Andes or the Rockies or unusual names like the Matterhorn
names of continents (Asia, Europe)
names of islands (Easter Island, Maui, Key West) except with island chains like the Aleutians, the Hebrides, or the Canary Islands

Do use the before:

names of rivers, oceans and seas: the Nile, the Pacific
points on the globe: the Equator, the North Pole
geographical areas: the Middle East, the West
deserts, forests, gulfs, and peninsulas: the Sahara, the Persian Gulf, the Black Forest, the Iberian Peninsula

Omission of Articles

Some common types of nouns that don't take an article are:

Names of languages and nationalities: Chinese, English, Spanish, Russian
Names of sports: volleyball, hockey, baseball
Names of academic subjects: mathematics, biology, history, computer science

Present Perfect - Simple Past

2009-10-14T08:06:00.000-07:00

Present Perfect - Simple Past

Present Perfect
[has/have + past participle]

1. Present perfect - form
The present perfect of any verb is composed of two elements : the appropriate form of the auxiliary verb to have (present tense), plus the past participle of the main verb. The past participle of a regular verb is base+ed, e.g. played, arrived, looked. For irregular verbs, see the Table of irregular verbs in the section called 'Verbs'.
Affirmative

Subject
to have
past participle
She
has
visited
Negative

Subject
to have + not
past participle
She
hasn't
visited
Interrogative

to have
subject
past participle
Has
she
visited..?
Interrogative negative
to have + not subject past participle
Hasn't she visited...?
Example: to walk, present perfect
Affirmative
Negative
Interrogative
I have walked
I haven't walked
Have I walked?
You have walked
You haven't walked
Have you walked?
He, she, it has walked
He, she, it hasn't walked
Has he,she,it walked
We have walked
We haven't walked
Have we walked?
You have walked
You haven't walked
Have you walked?
They have walked
They haven't walked
Have they walked?

2. Present perfect, function
The Present Perfect is used to indicate a link between the present and the past. The time of the action is before now but not specified, and we are often more interested in the result than in the action itself.
BE CAREFUL! There may be a verb tense in your language with a similar form, but the meaning is probably NOT the same.

The present perfect is used to describe:
1.An action or situation that started in the past and continues in the present. Example: I have lived in Bristol since 1984 (= and I still do.)

2. An action performed during a period that has not yet finished. Example: She has been to the cinema twice this week (= and the week isn't over yet.)

3. A repeated action in an unspecified period between the past and now. Example: We have visited Portugal several times.

4. An action that was completed in the very recent past, (expressed by 'just'). Example: I have just finished my work.

5. An action when the time is not important. Example: He has read 'War and Peace'. (the result of his reading is important)
Note: When we want to give or ask details about when, where, who, we use the simple past. Example: He read 'War and Peace' last week.

Examples:

1. Actions started in the past and continuing in the present.
a. They haven't lived here for years.
b. She has worked in the bank for five years.
c. We have had the same car for ten years.
d. Have you played the piano since you were a child?

2. When the time period referred to has not finished.
a. I have worked hard this week.
b. It has rained a lot this year.
c. We haven't seen her today.

3. Actions repeated in an unspecified period between the past and now.
a. They have seen that film six times.
b. It has happened several times already.
c. She has visited them frequently.
d. We have eaten at that restaurant many times.

4. Actions completed in the very recent past (+just).
a. Have you just finished work?
b. I have just eaten.
c. We have just seen her.
d. Has he just left?

5. When the precise time of the action is not important or not known.
a. Someone has eaten my soup!
b. Have you seen 'Gone with the Wind'?
c. She's studied Japanese, Russian and English.

SIMPLE PAST

BE CAREFUL! The simple past in English may look like a tense in your own language, but the meaning may be different.

1. Simple past, form
Regular verbs: base+ed
e.g. walked, showed, watched, played, smiled, stopped

Irregular verbs: see list in verbs
Simple past, be, have, do:
Subject

Verb
Be

Have

Do
I

was

had

did
You

were

had

did
He, she, it

was

had

did
We

were

had

did
You

were

had

did
They

were

had

did

Affirmative
a. I was in Japan last year
b. She had a headache yesterday.
c. We did our homework last night.

Negative and interrogative
Note: For the negative and interrogative simple past form of "do" as an ordinary verb, use the auxiliary "do", e.g. We didn't do our homework last night. The negative of "have" in the simple past is usually formed using the auxiliary "do", but sometimes by simply adding not or the contraction "n't".
The interrogative form of "have" in the simple past normally uses the auxiliary "do".

* They weren't in Rio last summer.
* We hadn't any money.
* We didn't have time to visit the Eiffel Tower.
* We didn't do our exercises this morning.
* Were they in Iceland last January?
* Did you have a bicycle when you were a boy?
* Did you do much climbing in Switzerland?

Simple past, regular verbs
Affirmative
Subject
verb + ed

I
washed

Negative
Subject
did not
infinitive without to
They
didn't
visit ...
Interrogative
Did
subject
infinitive without to
Did
she
arrive...?
Interrogative negative
Did not
subject
infinitive without to
Didn't
you
like..?

Example: to walk, simple past.

Affirmative

Negative

Interrogative
I walked
I didn't walk
Did I walk?
You walked
You didn't walk
Did you walk?
He,she,it walked
He didn't walk
Did he walk?
We walked
We didn't walk
Did we walk?
You walked
You didn't walk
Did you walk?
They walked
They didn't walk
Did they walk?

Note: For the negative and interrogative form of all verbs in the simple past, always use the auxiliary 'did''.

Examples: Simple past, irregular verbs

to go
a. He went to a club last night.
b. Did he go to the cinema last night?
c. He didn't go to bed early last night.

to give
d. We gave her a doll for her birthday.
e. They didn't give John their new address.
f. Did Barry give you my passport?

to come
g. My parents came to visit me last July.
h. We didn't come because it was raining.
i. Did he come to your party last week?

2. Simple past, function
The simple past is used to talk about a completed action in a time before now. Duration is not important. The time of the action can be in the recent past or the distant past.

* John Cabot sailed to America in 1498.
* My father died last year.
* He lived in Fiji in 1976.
* We crossed the Channel yesterday.

You always use the simple past when you say when something happened, so it is associated with certain past time expressions
Examples:

* frequency:
often, sometimes, always;
* a definite point in time:
last week, when I was a child, yesterday, six weeks ago.
* an indefinite point in time:
the other day, ages ago, a long time ago etc.

Note: the word ago is a useful way of expressing the distance into the past. It is placed after the period of time e.g. a week ago, three years ago, a minute ago.

Examples:
a. Yesterday, I arrived in Geneva.
b. She finished her work at seven o'clock.
c. We saw a good film last week.
d. I went to the theatre last night.
e. She played the piano when she was a child.
f. He sent me a letter six months ago.
g. Peter left five minutes ago.

Simple Present – Present Progressive

2009-10-14T08:02:00.000-07:00

Simple Present – Present Progressive

Present Progressive
Notes:

1. The written lesson is below.
2. Links to quizzes, tests, etc. are to the left.

The present progressive is formed by combining the verb "to be" with the present participle. (The present participle is merely the "-ing" form of a verb.)

I am studying.
I am studying with María.

In English, present progressive can be used to describe what is happening now, or what will happen in the future.

I am studying now.
I am studying with María tonight.

In Spanish, the present progressive is only used to describe an action that is in the process of taking place. It is not used for future actions.

I am studying now.
(use present progressive)
I am studying with María tonight.
(do not use present progressive)

To form the present progressive in Spanish, combine a form of "estar" with the present participle.

Estoy hablando.
I am speaking.
Juan está comiendo.
John is eating.
María está escribiendo una carta.
Mary is writing a letter.

In order to form the present progressive, you must know how to conjugate the verb estar, and how to form the present participle. You already know how to conjugate the verb estar:

estar
estoy
estás
está
estamos
estáis
están

To form the present participle of regular -ar verbs, add -ando to the stem of the verb.

hablar: hablando
(hablar - ar + ando)
trabajar: trabajando
(trabajar - ar + ando)
estudiar: estudiando
(estudiar - ar + ando)

To form the present participle of regular -er and -ir verbs, add -iendo to the stem of the verb.

comer: comiendo
(comer - er + iendo)
hacer: haciendo
(hacer - er + iendo)
vivir: viviendo
(vivir - ir + iendo)
escribir: escribiendo
(escribir - ir + iendo)

To form the present participle of -ir stem changing verbs, change e:i and o:u in the stem, and then add -iendo to the stem of the verb.

servir: sirviendo
pedir: pidiendo
decir: diciendo
dormir: durmiendo
morir: muriendo
poder: pudiendo

Sometimes when forming the present participle it is necessary to change the spelling of a word so that it agrees with the way it is pronounced. We call this an "orthographic" change. Here are some common examples:

caer: cayendo
creer: creyendo
huir: huyendo
ir: yendo
influir: influyendo
oír: oyendo
traer: trayendo
leer: leyendo
seguir: siguiendo

The following examples illustrate the rules for forming the present participle.

hablar: hablando (-ar)
comer: comiendo (-er)
vivir: viviendo (-ir)
decir: diciendo (e:i)
dormir: durmiendo (o:u)
leer: leyendo (orthographic)
seguir: siguiendo (orthographic)

To form the present progressive, simply conjugate the verb estar to agree with the subject of the sentence, and follow it with the present participle.

Juan está comiendo pan.
John is eating bread.
María y Carmen están hablando con nosotros.
Mary and Carmen are speaking with us.

Remember, only use the present progressive for actions that are "in progress." Compare the uses of the present indicative with the uses of the present progressive.

Estudio español. (Present Indicative)
I study Spanish.
I am studying Spanish (these days).
I do study Spanish.
Estoy estudiando español. (Present Progressive)
I am studying (right now, at this moment) Spanish.

It is important to remember that you would never use the present progressive to say something like "We are going to Spain this summer." Use present progressive only for actions that are "in progress."
Let's add two more verb flashcards: one for present progressive and one for practice in forming the present participle:
Verb Flashcards
Complete List

Present Progressive
estar + present participle
I am speaking (right now, at this moment)
Never use present progressive for something that will occur in the future.

Present Participle (-ando, -iendo, yendo)
hablar - hablando (-ar)
comer - comiendo (-er)
vivir - viviendo (-ir)
decir - diciendo (e:i)
dormir - durmiendo (o:u)
leer - leyendo (orthographic)
seguir: siguiendo (orthographic)

Simple Present

Ada beberapa penggunaan dari simple present tense, yaitu :
untuk menyatakan kegiatan yang berulang untuk menyatakan generalisasi atau kegiatan yang biasa berlangsung. Untuk menyetakan kegiatan saat ini. Untuk lebih jelasnya perhatikan penjelesan di bawah ini

1. Repeated Actions (Kegiatan berulang)
Simple present dapat digunakan untuk menyatakan gagasan atau kegiatan yang dilakukan sering dilakukan berulangkali seperti bangun tidur, atau kebiasaan seperti berolahraga, jadwal pemberangkatan kendaraan dan lain sebagainya, kegiatan tersebut dapat berupa kebiasaan, hobby, kegiatan sehari-hari, jadwal, dan juga kebiasaan yang selalu tidak dilakukan.
Dari gambar diatas tanda silang warna biru adalah kejadian yang dilakukan, jadi kejadian tersebut selain dilakukan saat ini (persent) juga dilakukan pada waktu lampau (past) dan yang akan datang (future)

EXAMPLES:

* I play tennis.
* She does not play tennis.
* The train leaves every morning at 8 am.
* The train does not leave at 9am.
* She always forgets her purse.
* He never forgets his wallet.
* Every twelve months, the Earth circles the sun.
* The sun does not circle the Earth.

2. Menyatakan Kebenaran atau keadaan yang umum (Facts or Generalizations)

Simple Present dapat juga digunakan untuk mengekspresikan suatu kejadian yang benar pada masa lampau, sekarang maupun yang akan datang, misalnya matahari terbit dari barat, satu jam 360 menit dan lain sebagainya. Selain itu Simple Present juga digunakan untuk menyatakan generalisasi (keadaan yang umum) terhadap pikiran orang, misalnya orang batak suka musik, burung mempunyai sayap dan lain sebagainya
Perhatikan gambar berikut untuk lebih jelasnya
.
EXAMPLES:

* Cats like milk.
* Birds do not like milk.
* Jakarta is in Indonesia
* Surabaya is not in the United Kingdom.
* Windows are made of glass.
* Windows are not made of wood.
* Jakarta is a small city. (It is not important that this fact is untrue.)

3. Keadaan Sekarang Now (Non-Continuous Verbs)

Simple Present digunakan juga untuk menyatakan kegiatan yang berlangsung maupun tidak berlangsung saat ini secasra spontan. Namun hanya bisa digunakan dengan Non-continuous Verbs dan Mixed Verbs.

EXAMPLES:

* I am here now.
* She is not here now.
* He needs help right now.
* He does not need help now.
* He has a car.

Diterjemahkan dari : englishpage.com

PRESENT artinya adalah kini, sekarang.
Rumusnya:
Positif: S + V1 (s/es)
Negatif: S + DO/DOES + NOT + V1
Tanya: DO/DOES + S + V1

Contoh Kalimat Positif:

* I drink coffee
* She drinks coffe
* We drink coffee

Ya, sengaja pelajaran Tense bahasa inggris ini dibuat simple saja agar cepat faham. Anda perlu mengembangkannya sendiri misalnya dengan membuat 100 contoh sendiri. Pasti Anda perlu kamus juga, karena belajar tenses lalu mentok dengan suatu kata kerja maka biasanya tidak jadi, hehe..

Cara Membaca Rumus:

S artinya Subject, V1 artinya Verb1 atau kata kerja bentuk pertama. Garis miring artinya ya Atau dong!.
Kapan pakai S atau ES dan kapan tidak?
Kalau Subjectnya He, She, It, John, Mufli, Ellen atau Orang ketiga TUNGGAL maka kata kerjanya tambah S atau ES. Tidak sembarang tambah S atau ES juga nih, ada daftarnya. Daftarnya itu bayak sekali.

Di atas tadi ada istilah Orang Ketiga Tunggal, maksudnya gini: Orang ketiga adalah orang yang kita bicarakan, yang kita omongin. Sedangkan orang pertama ya yang bicara. Orang kedua lawan bicara. Tunggal ya satu. Jadi orang ketiga tunggal adalah orang yang kita bicarakan dan satu saja dia itu. Misalnya kita berdua ngomongin John Scoping. Yang ngomong saya, yang dengar Anda, yang dibicarakan John Scoping (orang ketiga tunggal).

John Scoping belajar Tenses.
John Scoping learnS english.
Tidak bisa LearnES, mengapa? ya memang begitu!. Tetapi yang ini malah tambah ES:
John Scoping goES to School (tambah ES).
Kalimat Negatif Present Tense
Bentuk Negatif, artinya menyatakan TIDAK. Maka sesuai rumus Present Tense, setelah SUBJECT ditambah DO atau DOES, baru NOT, lalu tambah kata kerja bentuk pertama tanpa S atau ES lagi. S atau ES nya dimana? Sudah di doES tadi.

Untuk I, WE, YOU, THEY tambah DO
Untuk SHE, HE, IT, Mufli, Ellen tambah DOES

I do not drink coffee.
She does not drink coffee.
John Scoping does not learn english.

Coba perhatikan She does not drink coffee. Drink nya tidak pake S lagi, pindah ke doES. Biasakan saja, Present Simple Tense ini sepertinya rumit tetapi kalau faham maka enak banget. Ulangi saja baca dari atas 10 kali lagi, biar meresap benar, hehe.. Bikin juga 10 contoh Anda sendiri dengan kata kerja yang berbeda. Yes, belajar bahasa Inggris tak boleh manja, harus aktif, baru akan bisa.
Kalimat Tanya Present Tense
Kalimat tanya untuk Present Tense sesuai rumus diatas, atau saya tulis lagi seperti ini:
Tanya: DO/DOES + S + V1

Sama saja pasangannya. Untuk I, WE, YOU, THEY gunakan DO. Untuk SHE, HE, IT, Mufli, Ellen gunakan DOES. Contohnya begini:

Kalimat positifnya: I drink coffee
Kalimat tanya menjadi: DO you drink cofee?
Kalimat positif: She drinks coffe
Kalimat tanya: DOES She drink coffee?

Kalimat tanya seperti diatas disebut juga YES/NO Question. Karena jawabannya memang Yes atau No. Do You drink coffee? “Yes I do” jawabnya. Atau bisa bisa dijawab dengan lengkap: “Yes, I do drink coffee”. Dihilangkan DO nya juga boleh, menjadi kalimat positif lagi: “Yes I drink coffee”.
Ya, memang benar kalau Present Tense ini lebih rumit dibandingkan dengan Present Continuous Tense karena tiba-tiba kok pake DO, eh untuk orang ketiga tunggal pakai DOES segala, hehe.. Kalau dalam Present Continuous Tense nanti tinggal dibalik doang.

OTHERS, THE OTHER S & ANOTHERS

2009-10-14T07:53:00.000-07:00

OTHERS, THE OTHERS, & ANOTHERS

Kata other, another, dan others dapat diartikan dengan : yang lain atau lainnya. Ketiga kata tersebut sangat mudah membingungkan. Maka untuk menentukan bagaimana menggunakannya dengan tepat masing-masing kata itu harus diperhatikan empat hal.

1. Jika kata itu singular (tunggal) atau plural (jamak).
2. Jika kata itu definite –the- (tentu) atau indefinite –a- (tak tentu)
3. Jika kata itu berfungsi sebagai adjective yang menerangkan noun atau senantiasa bersama dengan noun.
4. Jika kata itu berfungsi sebagai pronoun yang dapat berdiri sendiri.

Perhatikanlah contoh-contoh berikut :
a. I have another (adj.) book
b. I have another (pron.)

“Perhatikan bahwa another digunakan hanya untuk menunjuk kepada an indefinite (tak tentu). Dan dengan benda tunggal (singular)”

c. I have other (adj.) books.
d. I have others. (pron)
e. I have the other book (adj.)
f. I have the other (pron.)
g. I have the other books (adj.)
h. I have the others (pron).

“Perhatikan bahwa Others hanya digunakan sebagai plural pronoun yang tidak bersama dengan noun(dapat berdiri sendiri). Sedangkan other dapat digunakan untuk semuanya”

i. I have three books, two are mine. The other book is yours. (The others is yours).
j. I have three books, one is mine. The others are yours. (The others are yours).
k. If you are still thirsty, I’ll make another pot of coffee.

Example :

OTHER -- the singular form. The word refers to something that is different from something else. For instance, Director A makes a movie based on a famous novel. Director B makes a different movie based on the same novel.

Luke: "Did you like Director A's movie?"
Ted: "Yes, but I liked the OTHER version much better."

Luke: "What do you think of my new wrist watch?" [On his right wrist.]
Ted: "I think you should wear it on your OTHER wrist."

Two senators write two different pieces of legislation about the same topic. "I like Senator Luke's legislation, but the OTHER one will probably be approved."

So, when we use the singular word "other," we are actually referring to something different from something else: X is fine, but I think the OTHER ["Y"] is more acceptable.

*****

OTHERS -- the plural form, for more than one "other"

Some essays are easy to read; OTHERS are much more difficult.

Many people chose to vote in the election. OTHERS simply stayed at home, not interested in voting at all. [OTHERS clearly indicates the "different" or "non-voting" people.]

*****

THE OTHERS -- same as above, but used in cases where the article "the" is necessary.

Luke: "Would you like to have THESE shirts?"
Ted: "No, I think THE OTHERS look more presentable."

The "chosen" people lived in the wealthy homes; all THE OTHERS lived in very poor houses. ["The others" in this example means "the people who are NOT wealthy" or THE OTHERS.]

*****

ANOTHER -- The dictionary definition is this: "different or distinct from the one first considered" OR "additional" OR "later."

Different or distinct --

Luke: "Are you going to write your essay about global warming?"
Ted: "I had thought I would, but I have changed my mind and will write on ANOTHER topic."

Additional --

Luke: "Did you get enough to eat?"
Ted: "No, I think I'll have another piece of pie."

Later --

Luke: "Are you taking a trip this weekend?"
Ted: "I think I'll wait until ANOTHER time."

*****

2009-10-13T22:48:00.000-07:00

VOIP (Voice Over IP)

Pada jaringan suara konvesional pesawat telepon langsung terhubung dengan PABX (Privat Automated Branch exchange) atau jika milik TELKOM terhubung langsung dengan STO (Sentral telepon Otomat) terdekat. Dalam STO ini ada daftar nomor-nomor telepon yang disusun secara bertingkat sesuai dengan daerah cakupannya. Jika dari pesawat telepon tersebut mau menghubungi rekan yang lain maka tuts pesawat telepon yang ditekan akan menginformasikan lokasi yang dituju melalui nada-nada DTMF, kemudian jaringan akan secara otomatis menghubungkan kedua titik tersebut.

Bentuk paling sederhana dalam sistem VoIP adalah dua buah komputer terhubung dengan internet. Syarat-syarat dasar untuk mengadakan koneksi VoIP adalah komputer yang terhubung ke internet, mempunyai kartu suara yang dihubungkan dengan speaker dan mikropon. Dengan dukungan perangkat lunak khusus, kedua pemakai komputer bisa saling terhubung dalam koneksi VoIP satu sama lain. Aplikasi VoIP dan Keamanannya

Salah satu aplikasi VoIP yang tersedia adalah Skype. Skype adalah [[software]] aplikasi komunikasi suara berbasis IP melalui internet antara sesama pengguna Skype. Pada saat menggunakan Skype maka pengguna Skype yang sedang online akan mencari pengguna Skype lainnya lalu mulai membangun jaringan untuk menemukan pengguna-pengguna lainnya. Skype memiliki berbagai macam fitur yang dapat memudahkan penggunanya. Skype juga dilengkapi dengan SkypeOut dan SkypeIn yang memungkinkan pengguna Skype untuk berhubungan dengan pengguna telepon konvensional dan telepon genggam.
Skype menggunakan protokol HTTP untuk berkomunikasi dengan Skype server untuk otentikasi username/password dan registrasi dengan Skype directory server. Versi modifikasi dari protokol HTTP digunakan untuk berkomunikasi dengan sesama Skype client. Keuntungan yang dimiliki aplikasi ini adalah tersedianya layanan keamanan dalam pentransmisian data yang berupa suara. Layanan keamanan yang diberikan adalah sebagai berikut :

* Privacy

Skype menggunakan AES (Advanced Encryption Standard) 256-bit untuk proses enkripsi dengan total probabilitas percobaan kunci (brute-force attack) sebanyak 1,1 x E-77 kali, sedangkan untuk proses pertukaran kunci (key exchange) simetriknya menggunakan RSA 1024-bit. Public key pengguna akan disertifikasi oleh Skype server pada saat login dengan menggunakan sertifikat RSA 1536 atau 2048-bit. Skype secara otomatis akan mengenkripsi semua data sebelum ditransmisikan melalui internet.

* Authentication

Setiap pengguna Skype memiliki sebuah username dan sebuah password. Dan setiap username memiliki sebuah alamat e-mail yang teregistrasi. Untuk masuk ke sistem Skype , pengguna harus menyertakan pasangan username dan passwordnya. Jika pengguna lupa password tersebut maka Skype akan mengubahnya dan mengirimkan password yang baru ke alamat e-mail pengguna yang sudah teregistrasi. Pendekatan ini dikenal dengan E-mail Based Identification and Authentication. Dikarenakan Skype merupakan sistem komunikasi suara maka setiap penggunanya dapat secara langsung mengidentifikasi lawan bicaranya melalui suaranya.

Keuntungan VoIP

* Biaya lebih rendah untuk sambungan langsung jarak jauh. Penekanan utama dari VoIP adalah biaya. Dengan dua lokasi yang terhubung dengan internet maka biaya percakapan menjadi sangat rendah.
* Memanfaatkan infrastruktur jaringan data yang sudah ada untuk suara. Berguna jika perusahaan sudah mempunyai jaringan. Jika memungkinkan jaringan yang ada bisa dibangun jaringan VoIP dengan mudah. Tidak diperlukan tambahan biaya bulanan untuk penambahan komunikasi suara.
* Penggunaan bandwidth yang lebih kecil daripada telepon biasa. Dengan majunya teknologi penggunaan bandwidth untuk voice sekarang ini menjadi sangat kecil. Teknik pemampatan data memungkinkan suara hanya membutuhkan sekitar 8kbps bandwidth.

Kelemahan dari VoIP

* Kualitas suara tidak sejernih Telkom. Merupakan efek dari kompresi suara dengan bandwidth kecil maka akan ada penurunan kualitas suara dibandingkan jaringan PSTN konvensional. Namun jika koneksi internet yang digunakan adalah koneksi internet pita-lebar / broadband seperti Telkom Speedy, maka kualitas suara akan jernih - bahkan lebih jernih dari sambungan Telkom dan tidak terputus-putus.
* Ada jeda dalam berkomunikasi. Proses perubahan data menjadi suara, jeda jaringan, membuat adanya jeda dalam komunikasi dengan menggunakan VoIP. Kecuali jika menggunakan koneksi Broadband (lihat di poin atas).
* Regulasi dari pemerintah RI membatasi penggunaan untuk disambung ke jaringan milik Telkom.
* Jika belum terhubung secara 24 jam ke internet perlu janji untuk saling berhubungan.