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Tuesday, 29 January 2013

Sistem Sokongan Keputusan (Decision Support System)


1.      Pengenalan DSS

Satu sistem sokongan keputusan (DSS) adalah satu sistem maklumat berasaskan komputer yang menyokong perniagaan atau aktiviti organisasi membuat keputusan.DSSs berkhidmat pengurusan, operasi dan tahap perancangan sesebuah organisasi dan membantu untuk membuat keputusan, yang mungkin pesat berubah dan tidak mudah ditentukan terlebih dahulu. Sistem sokongan keputusan boleh menjadi sama ada berkomputer sepenuhnya, manusia atau gabungan kedua-duanya. DSS termasuk sistem berasaskan pengetahuan.

DSS yang direka bentuk adalah satu sistem interaktif berasaskan perisian yang bertujuan untuk membantu pembuat keputusan menyusun maklumat yang berguna daripada gabungan data dokumen, mentah, dan pengetahuan peribadi, atau model perniagaan untuk mengenal pasti dan menyelesaikan masalah dan membuat keputusan.

Maklumat tipikal bahawa keputusan permohonan sokongan mungkin mengumpul dan membentangkan termasuk:
  • Inventori aset maklumat (termasuk legasi dan hubungan sumber data, kiub, gudang data, dan data mart)
  • Perbandingan angka jualan antara satu tempoh dan seterusnya
  • Unjuran angka pendapatan berdasarkan jualan produk andaian.

 Objektif DSS

  • Bantu sediakan sokongan kepada pengurus dalam proses pembuatan keputusan
  • Bantu pengurus bukan ganti pengurus dalam pembuatan keputusan.
  • Bantu keberkesanan proses membuat keputusan berbanding kecekapan.

Manfaat Daripada DSS

  1. Meningkatkan kecekapan peribadi
  2. Mempercepatkan proses membuat keputusan
  3. Meningkatkan kawalan organisasi
  4. Menggalakkan penerokaan dan penemuan di bahagian pembuat keputusan
  5. Mempercepatkan penyelesaian masalah dalam sesebuah organisasi
  6. Memudahkan komunikasi antara perorangan
  7. Menggalakkan pembelajaran atau latihan
  8. Menjana bukti baru dalam sokongan keputusan
  9. Mewujudkan kelebihan daya saingan berbanding persaingan
  10. mendedahkan pendekatan baru untuk memikirkan tentang penyelesaian masalah
  11. Membantu mengautomasikan proses pengurusan
  12. Mewujudkan idea-idea berinovatif untuk meningkatkan prestasi

Tujuan menggunakan DSS:

  • menigkatkan keberkesana di peringkat pengurusan untuk memberi keputusan terutama dalam tugas yang kompleks.
  • menggunakan data dan model untuk membuat keputusan. Untuk menyelesaikan masalah berstruktur,semi berstruktur, tak berstruktur.
  • Pihak yang membuat keputusan perlu membuat keputusan yang tepat jitu, terkini, agar keputusan berkualiti dan efektif..
  • Sistem yang memberi kemudahan kpd pengurus untuk menyelesaikan mslah berstruktur, semi berstruktur, tak berstruktur.

Monday, 28 January 2013

Air Conditioning Buying Guide & Tips

With myriad air conditioners available --- split system, window/wall or mobile (movable) units --- our air conditioning guide makes sense of terminology, like reverse cycle and inverter, so you can decide which air con suits you. ?




Room Size Vs. Air Conditioner Capacity


Match the air conditioning unit to the size of the room it's cooling. As a rule of thumb, the bigger the room, the more powerful an air con unit will have to be to cool it:
  • Underpowered air conditioners will have to work harder, wasting energy.
  • Overpowered air conditioners are an unnecessary expense.

How Much Capacity Will I Need?

Air conditioners are rated by BTU (British Thermal Unit) and power output, in kilowatts (kW). To work out the approximate sized air con you'll need, apply this simple formula:
  • Bedroom: 80 watts (0.080kW) per square metre (length by width). For example, a 16m² bedroom should need around 1.28kW of air conditioning
  • Living room: 125 watts (0.125kW) per square metre. For example, a 30m² living room should require around 3.75kW
Proximity to the kitchen and appliances increases a room's required cooling.

Which Type Of Air Conditioner?

  • Ducted: Cool multiple rooms through a large cooling fan, which sits outside and pumps cool air around the building through ducts, which are housed in the ceiling cavity.
  • Window units: Mounted through a window/wall. These are excellent for small rooms.
  • Split system: The cooling unit is installed outside, with the fans mounted inside. A split system air conditioner is suited to cooling one or more adjoining rooms.
  • Multi-split system: Utilising one outdoor unit, with multiple fan units inside to distribute the cool air throughout the house.
  • Portable: Small, light and mobile, so they're movable from room to room. Portable units have a low power output, suited to small spaces -\ apartments and renters.
  • Evaporative coolers: Appear like cheaper versions of portable air conditioners, but do not use refrigerant technology. They work by drawing air past a special water-cooled filter system.

Technical Terms You Should Know

Reverse cycle: The reverse cycle air conditioner internally reverses its operation to provide heating or cooling, as required.
Inverter system: Constantly alters fan and motor speeds. This enables faster cooling of a room, and the inverter air conditioner doesn't have to switch itself on and off to maintain a constant temperature.

Energy Efficiency: The Energy Label


Registered suppliers supplying registrable goods must affix the Energy Label on the units that they supply in Singapore. The Energy Label shall be affixed only after the National Environment Agency (NEA) has issued the Certificate of Registration (COR) for the model. Retailers are only allowed to display models that have the label affixed on them.
The more ticks, the better the appliance’s energy efficiency.
Manufacturers of inverter systems claim that they are 30 per cent more efficient during partial load.

Is it Noisy?

If you're considering an outdoor air conditioning unit, check the relevant noise level regulations.

Are Filters Necessary?

Yes. Good air conditioning units will use filters to prevent bacteria and allergens being recycled through the room.
  • It's important to clean the filter every few weeks.
  • Some units have an indicator to show when the filter needs changing.

Positioning Is Important

  • Avoid positioning the air conditioning unit on the side of the house that gets the most sun; this will cause it to be less efficient.
  • For efficient cooling, mount the unit high in the room --- cool air sinks.


Installation

Do not attempt to install a split or ducted system without holding the appropriate licenses. This will also void you warranty.

Simple Air Conditioning Choices

  • Room size: Match the power of an air conditioner to the room size.
  • Type: Choose from central ducted, window units, split systems and portable.
  • Filters: Prevent bacteria and allergens from being recycled through the room.



source : http://www.harveynorman.com.my/home-appliances/cooling-ambient-air-products/air-conditioning.html/