The document summarizes the economic motivations and beneficiaries behind the 1991 Gulf War and subsequent wars. It argues that while the US claimed to liberate Kuwait, the true goals were economic gains for the US and its allies. Much of the war costs were paid by increased oil profits, with over $60 billion going to oil companies and Gulf governments, some of which later supported additional US-led wars bringing further economic benefits through war spending and control of oil infrastructure.
The document summarizes the economic motivations and beneficiaries behind the 1991 Gulf War and subsequent wars. It argues that while the US claimed to liberate Kuwait, the true goals were economic gains for the US and its allies. Much of the war costs were paid by increased oil profits, with over $60 billion going to oil companies and Gulf governments, some of which later supported additional US-led wars bringing further economic benefits through war spending and control of oil infrastructure.
The document discusses several key points about Python:
1. It summarizes praise for Python from programmers and companies like Google, NASA, and CCP Games, highlighting Python's simplicity, compactness, and ability to quickly develop applications.
2. It introduces common Python concepts like strings, lists, sequences, namespaces, polymorphism, and duck typing. Strings can be manipulated using slicing and methods. Lists and other sequences support indexing, slicing, and iteration.
3. Python uses name-based rather than type-based polymorphism through duck typing - an object's capabilities are defined by its methods and properties rather than its class.
Python modules allow programmers to split code into multiple files for easier maintenance. A module is simply a Python file with a .py extension. The import statement is used to include modules. Modules can be organized into packages, which are directories containing an __init__.py file. Popular third party modules like ElementTree, Psyco, EasyGUI, SQLObject, and py.test make Python even more powerful.
The document introduces the Django web framework for Python. It provides an overview of Django's philosophies such as loose coupling, quick development and the DRY principle. It then demonstrates how to build a basic blog application in Django with models, views, templates and URLs. Finally, it discusses additional Django features like generic views and real-world code snippets.
The document discusses the benefits of exercise for both physical and mental health. It notes that regular exercise can reduce the risk of diseases like heart disease and diabetes, improve mood, and reduce feelings of stress and anxiety. The document recommends that adults get at least 150 minutes of moderate exercise or 75 minutes of vigorous exercise per week to gain these benefits.
The document contains repeated lines of text listing "back0 |0 next" without any other context or information provided. It is not possible to determine the essential meaning or purpose of the document from the limited information given.
The document reflects on life stages from childhood education through career and family life. It discusses the ups and downs experienced, from striving for success to losing a job. This leads to contemplating how to improve one's life by taking it easier, spending more time with loved ones, and focusing on shared goals and happiness. The conclusion encourages sharing this message to remember friends.
1. 一、前言
隨著無線網路簡便設定、免除佈線、隨時上網等優勢，加上政府逐步推廣無線寬頻上網，
無線網路的流行風潮已逐漸蔓延開來。目前無線網路的技術已由之前的 IEEE 802.11a
到目前的 IEEE 802.11g，速度也由 11Mbps 到 54Mbps，足足提升五倍之多。然而隨
著家庭與企業用戶在多媒體影音、資料備份等大量檔案傳輸的需求，54Mbps 的頻寬也
相形見拙，與有線網路的 10/100Mbps 甚至於 1Gbps 的傳輸速度比較起來更是只能望
其項背。因此，增加無線網路的傳輸速度與頻寬更是趨勢。
目前傳輸速度超越 IEEE 802.11g 54Mbps 的技術共有三項：Super G、IEEE 802.11n
以及 UWB。因目前已應用在產品上的為 Super G，以下將為您介紹 Super G 技術：
二、Super G 的由來
Super G 的技術是由 Atheros 這間以製造無線網路晶片的公司所提出。在 2003 年 4 月
底，該公司以 IEEE 802.11g 和 Draft 8.1 為基礎推出了 AR5001G，又稱為 Super
G（802.11b/g）；以及 AR5001X+，又稱為 Super A/G（802.11a/b/g）的無線網路晶
片，一舉將傳輸速度由 54Mbps 提升到 108Mbps。
在 2004 年 4 月，也就是 Super G 推出屆滿一週年的同時，Atheros 更宣布其 Super
2. G 技術可透過軟體更新的方式在增強模式中自動偵測鄰近基地台為 802.11b、802.11g
或是 Super G。換句話說，也就是使用 Atheros Super G 技術的網路卡可自動偵測附近
是否有 Super G 的基地台。若有，便可以最高 108Mbps 的速度來傳輸資料，若僅是
802.11b 或 802.11g 的基地台，則使用 11Mbps 或 54Mbps 來傳輸。
三、Super G 的高頻寬模式
Super G 提高頻寬的方法有兩種模式：
1. Base mode（基礎模式）：
透過 Packet Bursting（封包突發模式）、Fast Frame（快速訊框）、Compression（資
料壓縮）的方式讓實際網路傳輸速率可達 40Mbps。
2. Enhanced Mode（增加模式）也稱為 Dynamic Turbo：
透過頻道綑綁的方式擴充傳輸訊號頻寬。
四、Super G 的運用原理
4. 3. Compression（資料壓縮）
Super G 使用 Lempel Ziv 的演算法來壓縮/解壓縮資料。此演算法亦為 Winzip 或 Pkzip
等程式所運用。因其能壓縮後傳輸，接收時解壓縮。而壓縮後資訊很小，所以數據傳輸
更快，從而釋放出無線區域網路頻寬給其他設備進行傳輸。此外 Super G 無線產品使
用全硬體的機制來做壓縮及解壓縮，故可提高整體的網路性能。
4. Dynamic Turbo
Dynamic Turbo 是透過兩個無線通訊通道（radio channel）的無線電頻譜
（spectrum）來傳輸資料，就像是常見於 Switch 中 trunking 的技術，使用兩個或以上
的線路來增加整體頻寬。Dynamic Turbo 最明顯的效果便是資料傳輸率的加倍，另一個
則是擴大網路的有效範圍。透過此功能，工作站可以在原本 802.11g 傳輸速度為
18Mbps 的連結距離內達到 36Mbps 的連結速度，在 6Mbps 的距離達到 12Mbps 的速
度。透過 Dynamic Turbo 功能，不僅能將任何單一無線通訊通道技術的資料傳輸率增
加一倍，亦能擴充網路有效範圍。
在一般使用的情況，Dynamic Turbo 功能對第三者的無線網路或裝置沒有顯著的影響。
此外，當 Dynamic Turbo 網路偵測到附近有其他網路時，AP 將會自動重新設定為單
一 channel 模式，以利於其他非 Super G 無線網卡來連接，因此 Super G 可向下相容
5. 於 802.11b/g。
由於 Super G 並不是國際標準，僅是廠商自行開發讓速度倍增的新技術，因此欲享受
Super G 的高傳輸速率，建議使用同廠商、同晶片的 AP 與網卡，確保在相容性與傳輸
速度上不會有太大的問題。
五、結論
下一代的無線網路必然走向高傳輸速率，必須滿足高頻寬需求，並與 802.11a、b、g 皆
能相容。而在無線網路普及化、家庭化的發展趨勢下，影音多媒體通訊將會是無線網路
標準下一個追尋的目標。此外在傳輸速度提升的同時，如何讓無線網路擁有高度的安全
性，又能兼顧易於設定、方便使用，也必將是下一個無線網路發展的議題。
六、附錄
IEEE 802.11X 規格列表：
6. ※聯強目前銷售支援 Super G 的產品
● D-Link 無線基地台
1. DWL-7100AP（支援 IEEE 802.11 a/b/g）
