0%

0921 Question

1. Car Waiting Time Model in Red Light

Traffic Engineering problem

Concept:

  • Green wave, you can go through a series of intersection without stopping.
  • Driver Reaction time: 1-2.5 seconds
  • Acceleration time: 2-4 seconds to reach the speed of the car in front of it

Math model

  • r=reaction time of each driver
  • a=acceleration time
  • n=number of cars in front of

$$
T=n(r+a)
$$

2. Update V.S. Upgrade

Update is small change

Upgrade is big change


In daily life

  • update is to make something more current or bring it up to date
  • Upgrade is to raise something to a higher standard

3. Sharpness V.S. Contrast

Sharpness refers to the clarity of the edges and fine details

  • Detect edge and combine the detected edges back into the original image
    $$
    I^{\prime}=I+\alpha\left(I-I_{\text {blurred }}\right)
    $$

Contrast refers to the difference in luminance or color that makes objects distinguishable in a image

  • Contrast stretching
    $$
    I^{\prime}=\frac{\left(I-I_{\min }\right)(255)}{I_{\max }-I_{\min }}
    $$

4. Vibration V.S. Saturation

Saturation: refers to the intensity of colors

  • Increasing it can make image more vivid
  • Change in saturation impacts all pixel
  • $S^{\prime}=S \times \text { factor }$

Vibration: more intelligent or selective forms of saturation

  • Increasing it would increase the intensity or the more muted color
  • Can protect certain colors like skin tone
  • $S^{\prime}=S \times(1+(\text { factor } \times(1-S)))$

5. Why Kefir Yogurt so Sour

Kefir: thinner consistency than Greek yogurt

  • Liquid form can accentuate the perception of sour taste
  • Ethanol production (乙醇), can enhance the sour perception