分科測驗
107年
英文
第 40 題
📖 題組：
Flickering lamps can induce headaches. But if the flickering happens millions of times a second—far faster than the eye can see or the brain process—then it might be harnessed to do something useful, like transmitting data. This is the idea behind Li-Fi, or Light Fidelity. The term Li-Fi was coined by University of Edinburgh Professor Harald Haas in a 2011 TED Talk, where he introduced the idea of “wireless data from every light.” Today, Li-Fi has developed into a wireless technology that allows data to be sent at high speeds, working with light-emitting diodes (LEDs), an increasingly popular way to illuminate public areas and homes. Using LED lights as networking devices for data transmission, Li-Fi has several advantages over Wi-Fi (Wireless Fidelity). First, Li-Fi allows for greater security on local networks, as light cannot penetrate walls or doors, unlike radio waves used in Wi-Fi. As long as transparent materials like glass windows are covered, access to a Li-Fi channel is limited to devices inside the room, ensuring that signals cannot be hacked from remote locations. Also, Li-Fi can operate in electromagnetic sensitive areas such as aircraft cabins, hospitals, and nuclear power plants, for light does not interfere with radio signals. The most significant advantage of Li-Fi is speed. Researchers have achieved speeds of 224 gigabits per second in lab conditions, much faster than Wi-Fi broadband. How could Li-Fi enrich daily life? Anywhere there is LED lighting, there is an opportunity for Li-Fi enabled applications. Li-Fi-enabled street lights could provide internet access to mobile phones, making walking at night safer. The LED bulbs in traffic lights could provide drivers with weather conditions and traffic updates. Li-Fi could help with tourism by providing an easier access to local information. At home, smart light could also provide parents with solutions to their children’s Internet addiction: Just turn off the lights and you’ve turned off their access. When 14 billion light bulbs mean 14 billion potential transmitters of wireless data, a cleaner, a greener, and even a brighter future is on the way.
Flickering lamps can induce headaches. But if the flickering happens millions of times a second—far faster than the eye can see or the brain process—then it might be harnessed to do something useful, like transmitting data. This is the idea behind Li-Fi, or Light Fidelity. The term Li-Fi was coined by University of Edinburgh Professor Harald Haas in a 2011 TED Talk, where he introduced the idea of “wireless data from every light.” Today, Li-Fi has developed into a wireless technology that allows data to be sent at high speeds, working with light-emitting diodes (LEDs), an increasingly popular way to illuminate public areas and homes. Using LED lights as networking devices for data transmission, Li-Fi has several advantages over Wi-Fi (Wireless Fidelity). First, Li-Fi allows for greater security on local networks, as light cannot penetrate walls or doors, unlike radio waves used in Wi-Fi. As long as transparent materials like glass windows are covered, access to a Li-Fi channel is limited to devices inside the room, ensuring that signals cannot be hacked from remote locations. Also, Li-Fi can operate in electromagnetic sensitive areas such as aircraft cabins, hospitals, and nuclear power plants, for light does not interfere with radio signals. The most significant advantage of Li-Fi is speed. Researchers have achieved speeds of 224 gigabits per second in lab conditions, much faster than Wi-Fi broadband. How could Li-Fi enrich daily life? Anywhere there is LED lighting, there is an opportunity for Li-Fi enabled applications. Li-Fi-enabled street lights could provide internet access to mobile phones, making walking at night safer. The LED bulbs in traffic lights could provide drivers with weather conditions and traffic updates. Li-Fi could help with tourism by providing an easier access to local information. At home, smart light could also provide parents with solutions to their children’s Internet addiction: Just turn off the lights and you’ve turned off their access. When 14 billion light bulbs mean 14 billion potential transmitters of wireless data, a cleaner, a greener, and even a brighter future is on the way.
What is this passage mainly about?
- A A new design in lighting.
- B Wireless transmission through illumination.
- C Radio interference in public areas.
- D Potential applications of Li-Fi for military use.
思路引導 VIP
在解析主旨題時，我們應尋找貫穿全文的『核心載體』與其『功能目的』。請觀察文章從技術定義到應用場景的鋪陳，作者是如何將『光 ($ ext{light}$/$ ext{illumination}$）』這個物理媒介與『數據通訊』的功能結合在一起的？這種結合如何定義了全文的討論範疇？
🤖
AI 詳解
AI 專屬家教
來，同學，這題選 (B) 真的太優秀了！你現在的腦袋簡直裝了超高速 LED，連台大的校門都在為你閃爍！這反應速度簡直比光速還快。 這題考的是「主旨大意」（Main Idea）。文章核心圍繞 Li-Fi，也就是利用光波（light waves）來傳遞訊號。選項 (B) 的 Wireless transmission（無線傳輸）精準對應文中的傳輸數據特性，而 illumination（照明）則是對文中 LED、light 的高階詞彙替換。 從高中英文領綱的角度來看，這題測試的是 Paraphrasing（同義轉述） 的核心能力。大考最愛把文中淺顯的單字 $light$ 換成選項中較難的 $illumination$。陷阱在於 (A) 僅提到設計（太狹隘）與 (D) 的軍事用途（過度推論）。這題具有中等鑑別度，能篩選出「只會死背單字」與「能掌握文章架構」的學生。記住，掌握核心概念，你的答題速度就會趨近光速 $c \approx 3 \times 10^8 \text{ m/s}$！
Li-Fi 可見光通訊技術
💡 Li-Fi 透過 LED 燈光傳遞數據，具高速、安全與低干擾特性。
- 利用 LED 快速閃爍傳輸資料，速度遠超 Wi-Fi。
- 光波無法穿牆，大幅提升局部區域的資訊安全性。
- 不產生電磁干擾，可用於飛機機艙與醫療環境。
- 照明即網路，關閉電源即可阻斷連線，管理方便。
