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Sunday, 27 October 2013

Chinese Scientists Create LiFi (Light Powered Internet)

Move over WiFi; successful experiments by a group of Xinhua, Shanghai based scientists have implied the possibilities of improving China’s online means by using the signals sent by light bulbs. This technology is called LiFi, a wireless communication using light as a carrier in place of the usual radio frequencies. This has the advantage of being able to use internet even near electromagnetic sensitive locations such as nuclear power plants and aircrafts, without causing any interference.



Earlier this month we reported about an experiment conducted by Chi Nan, a professor in Fudan University, Shanghai. Four computers in a one-wattage LED light were connected to the internet. Chi disclosed that a light bulb with inserted microchips was able to generate data rates with a speed of 150 mbps, faster than typical broadband in China. Chi under the information technology department of his university, is leading the research team for LiFi. This team includes researchers from the Shanghai Institute of Technical Physics. Professor Harald Haas from the University of Edinburgh was the first to demonstrate how a light bulb fitted with signal processing technology could stream high definition video to a computer. But his company released a statement suggesting they were just as surprised as everyone else about Chi’s claims of the connection speed.

LiFi offers a practical and resourceful solution for the local Chinese broadband. Chi reveals that the present wireless signal transmission is costly and inefficient. A big percentage of energy is also wasted on cell phone base stations, which consumes a lot of electricity on their cooling systems. Compared to these stations, there can be limitless number of light bulbs which can produce better broadband signals without consuming a lot of energy.

However, the team of scientists knew that this innovation still has a long way to go to be successful commercially.

“Wherever there is an LED light bulb, there is an Internet signal,” Chi says. However, turning off the light cuts the signal. Light, unlike radio frequencies, cannot go through walls. “If the light is blocked,” Chi continues, “The signal will be cut off”

Netizens are already anticipating the 10 sample kits which will be on display at the China International Industry Fair which will be launched on November 5 in Shanghai. LiFi is still under an experimental period.

[Image via Crewfone]

27 Oct 2013

Saturday, 19 October 2013

Battery Basic: Rechargeable Battery Knowledge Base



Tell me a bit more about rechargeable batteries, how are they different from primary or throwaway batteries?
 
Rechargeable batteries are of the same sizes (AA, AAA, C, D, Sc and 9V) and are intended for everyday use are the throwaway or primary batteries people use. The advantage of rechargeable batteries is that they can be recharged and reused up to a thousand times and generally they greatly outperform standard everyday throwaway leading brand batteries. 

The fact that rechargeable batteries can be used again and again represents a massive saving over their useful life. Rechargeable NiMH batteries are also very popular simply due to the fact that they are extremely environmentally friendly. Once charged, these rechargeable batteries can be used in the same way as you would with your previously throwaway batteries of the same size.
  
Why should I buy NiMH rechargeable batteries?
 
Better performance in driving electronics and huge money saving are the two major reasons to buy NiMH (Nickel metal Hydride) rechargeable batteries. They can be charged up to 500-1000 times and last longer than alkaline or NiCd batteries. 

NiMH batteries are ideally compatible with most consumer devices such as digital cameras, game boys, CD players, RC vehicles, PDA’s, portable two-way radios, flash units and many more high drain devices. One set of relatively inexpensive NiMH rechargeable batteries can save you from buying thousands if throwaway alkaline batteries. 



What are the primary advantages of NiMH batteries over Alkaline or other rechargeable batteries?


NiMH Batteries Have the Following Advantages :
  • Drive better performance with high-drain electronic devices
  • Large capacity for longer device operation. NiMH rechargeable batteries can last 2-4 times longer than alkaline throwaway batteries or NiCd rechargeable batteries
  • Long battery life, can be charged/discharged up to 500-1,000 cycles.
  • Extremely low battery cost per unit of device operation (such as every photo taken or every hour CD is played), providing very low cost of consumables for your electronics.
  • Stable performance due to flat discharge curve. NiMH battery will remain in high voltage during 80% of the usage cycle.
  • No memory effect for easy charging and usage.
  • Friendly to the Environment – no toxic chemical
 
What does battery “mAh” capacity mean?

mAh is a unit for measuring electric power over time. mAh is commonly used to describe the total amount of energy a battery can store at one time.

A battery rated for more mAh will power a phone for a longer amount of time, given the same usage pattern. The trade-off is that batteries with more mAh are generally also physically larger.

More technically, a higher mAh rating means the (fully-charged) battery can power a device that consumes more power and/or for a longer amount of time before becoming depleted and needing to be re-charged. For example, a battery rated at 1500 mAh can power a device drawing 100 milliamps for 15 hours, or a device drawing 150 milliamps for 10 hours.

The mAh capacity rating refers to the storage capacity available for a particular battery. A battery with a capacity rating of 1800 mAh could deliver a current of 1800mA for one hour. 

Higher mAh ratings for the same battery type will generally mean longer run times. This does not apply when comparing different types of batteries. This means that you may not be able to predict how long your electronic device will run just by looking at the capacity rating of a battery. When powering high drain electronic devices like digital cameras, computer peripherals, or portable music players, an alkaline battery will only deliver a small fraction of its rated capacity. 

For example AA alkaline batteries typically have a capacity rating of over 2,500 mAh and AA NiMH batteries have rated capacities of only 1,200 to 2,000 mAh. But when it comes to actually powering an electronic device like a digital camera, the NiMH batteries will often run the device for three or four times a long. Even comparing the capacity ratings of similar types of batteries won’t often work since different manufacturers can measure battery capacity in slightly different ways. 

A NiMH or NiCd battery is likely to deliver much closer to its rated capacity when it’s powering high drain devices. Alkaline batteries have a high rated capacity, but they can only deliver their full capacity if the power is used slowly. This means that a NiMH battery with a rated capacity of 1200 mAh can take many more photos than an alkaline battery with a rated capacity of 2,800.

How environmentally friendly are NiMH rechargeable batteries?

Rechargeable batteries have the greenest environmental credentials. Using rechargeable batteries reduces household waste massively. Globally, 15 billion ordinary batteries are thrown away every year, all of which end up in landfill sites. Rechargeable batteries can be reused again and again which significantly reduces the impact disposable batteries have on the environment.


How long can a rechargeable battery last over its life?

Let's say you are currently using ordinary throwaway batteries for your portable CD player and you replace the batteries once a week. For simplicity, let’s say there are 52 weeks in a year. You can recharge your NiMH rechargeable batteries 500 times.So the NiMH rechargeable battery can last 500 recharges / 50 weeks = 10 years. That means you could still be using the same batteries you buy today in 10 years time! Chances are that once you get into rechargeable batteries you will never use a throwaway again.

 

Resource:
http://www.all-battery.com/batterybasics.aspx
http://www.phonescoop.com/glossary/term.php?gid=194

Sunday, 13 October 2013

Pentaksiran Kerja Kursus ICT





1. Bahan Kerja Kursus ICT SPM
    Bahan Kerja Kursus (Assessment Form 4 & 5)
2. Borang-Borang Pentaksiran
    Manual Pentaksir
    Individual Score Sheet (ISF)
    Score Sheet Form (SSF)
   



Gajet ICT Terkini


Zaman IT serba canggih sekarang ini, semua orang hanya mahukan yang terkini, terbaik dan semua yang hebat-hebat belaka. Kalau nak diikutkan, memang tak terdaya untuk mengikuti arus permodenan ini. Namun masyarakat Malaysia amat gemar mencari gajet terkini dan seolah-olah sudah menjadi suatu trend masa kini! Berikut dipaparkan entri terkini mengenai gajet-gajet tersebut.

Smartphone
HTC DLX incoming to challenge Samsung Galaxy Note 2

Games

Pentaksiran Kerja Kursus Tingkatan 4

Jadual Pentaksiran Kerja Kursus ICT Tingkatan 4

BIL
PERKARA
TARIKH
TINDAKAN
1
2
3
4


5
Guru membimbing pelajar memahami kandungan dan keperluan aspek kerja kursusPelajar melaksanakan aspek kerja kursusGuru menyemak dan memasukkan markah pelajar dalam Borang ACFPelajar membuat semula aspek kerja kursus tersebut sekiranya tidak mendapat markah penuh (sekiranya ada)
Guru menyemak dan memasukkan markah terbaru pelajar dalam Borang ACF (sekiranya ada)

Guru ICT Tingkatan 4
Pelajar ICT Tingkatan 4
ASPEK
LA1.S01.1 Apply Correct Security Procedures Using Antivirus
Mac
LA1.S01.2 Apply correct security procedures using anti-spyware
Mac
LA1.S02.1 Locate and present information on the impact of ICT on society
Februari
LA2.S03.1 Assemble the components of a personal computer (PC)
April - Mei
LA2.S04.1 Install an operating system, application software and utility programs
Jun – Julai
LA2.S05.1 Explain the latest open source software available and the latest development in ICT
Julai - Ogos
LA3.S06.1 Crimp and test UTP cables
September
LA3.S06.2 Configure and test network
September
LA3.S07.1 Explain Latest development in networks and communications
September-Oktober
6
Guru mengisi markah pelajar ke dalam Borang ISF.M1
Februari – Oktober
Guru ICT Tingkatan 4
7
Guru mengisi markah pelajar ke dalam Borang BSF
Okt - Nov
8
Guru mendapatkan tandatangan pengesahan daripada Pengetua/PK1/Ketua Bidang bagi borang-borang berikut: I. ISF.M1 (Module 1)II. ISF.M2 (Module 2)III. ISF.M2 (Module 3)IV. BSF




April
SeptemberNovemberNovember
Guru ICT Tingkatan 4
Pengetua/
PK1/
Ketua Bidang
9
Guru menyerahkan salinan borang BSF kepada Ketua Panitia
November
Guru ICT Tingkatan 4