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dB

 µ¥½Ãº§ÀÇ ¾à¾î. »ó´ëÀü·Âºñ¿¡ ´ëÇÑ ·Î±×°ªÀÇ 1/10 °ªÀ¸·Î, 0.1 B(º§) °ú °°´Ù. ÁÖ : 1) µ¥½Ãº§Àº º§º¸´Ù ´õ ÀÛÀº °ªÀ¸·Î Ç¥ÇöµÇ°í ´õ Æí¸®ÇÏ°Ô »ç¿ëµÇ±â ¶§¹®¿¡ »ó´ëÀü·Âºñ¿¡ ´ëÇÑ ÀϹÝÀûÀΠǥÇö ¹æ¹ýÀÌ´Ù. dB ´Â ´ÙÀ½ ½Ä°ú °°ÀÌ ÁÖ¾îÁø´Ù.
 
 ¿©±â¼­, P 1  °ú P 2  ´Â ½ÇÁ¦ Àü·ÂÀÌ´Ù. Àü·Âºñ´Â Àü¾Ð E ¿Í ÀÓÇÇ´ø½º Z ÀÇ Ç×À¸·Î ¶Ç´Â Àü·ù I ¿Í ÀÓÇÇ´ø½º Z ÀÇ Ç×À¸·Î Ç¥ÇöµÉ ¼ö ÀÖ´Ù.
 
 ±×·¯¹Ç·Î, ¶ÇÇÑ dB ´Â ´ÙÀ½°ú °°ÀÌ ÁÖ¾îÁø´Ù.
 
 ¸¸¾à, Z 1  = Z 2  ¶ó¸é,
 
 °¡ µÈ´Ù. 2) dB ´Â ȸ·Î°¡ Á÷·Ä·Î ¿¬°áµÉ ¶§ dB ·Î Ç¥ÇöµÈ Àü·Â·¹º§À» ´ë¼öÀûÀ¸·Î ´õÇϰųª »¬ ¼ö Àֱ⠶§¹®¿¡, ´ë¼öÀû ºñÀ²À̳ª ¹éºÐÀ²º¸´Ù ´õ ¸¹ÀÌ »ç¿ëµÈ´Ù.
 Abbreviation for decibel(s). One tenth of the common logarithm of the ratio of relative powers, equal to 0.1 B (bel). Note 1: The decibel is the conventional relative power ratio, rather than the bel, for expressing relative powers because the decibel is smaller and therefore more convenient than the bel. The ratio in dB is given by
 
 where P 1  and P 2  are the actual powers. Power ratios may be expressed in terms of voltage and impedance, E and Z , or current and impedance, I and Z , since
 
 Thus dB is also given by
 
 If Z 1  = Z 2 , these become
 
 Note 2: The dB is used rather than arithmetic ratios or percentages because when circuits are connected in tandem, expressions of power level, in dB, may be arithmetically added and subtracted.
http://www.its.bldrdoc.gov/fs-1037/