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信噪比(signal to noise ratio,SNR)是MRI最基本的质量参数,其正确的概念表述应为()A、图像的亮度与暗度之比 B、两个像素的信号强度之比 C、两个体素的信号强度之比 D、图像的信号强度与背景强度之比 E、图像的信号与噪声之比

题目

信噪比(signal to noise ratio,SNR)是MRI最基本的质量参数,其正确的概念表述应为()

  • A、图像的亮度与暗度之比 
  • B、两个像素的信号强度之比 
  • C、两个体素的信号强度之比 
  • D、图像的信号强度与背景强度之比 
  • E、图像的信号与噪声之比

相似考题
更多“信噪比(signal to noise ratio,SNR”相关问题
  • 第1题:

    What is an advantage of an externally modulated laser over a directly modulated laser?()

    A. lower cost

    B. higher chirp

    C. easier to manufacture

    D. higher dispersion tolerance

    E. higher optical signal-to-noise ratio


    参考答案:D

  • 第2题:

    什么是RSRP?()

    A.The received power on the resource elements that carry cell-specific reference signals

    B.wideband power

    C.N times the Reference Signal Received Power divided by the total received power in the channel bandwidth

    D.Signal to Interference plus Noise Ratio


    参考答案:A

  • 第3题:

    信噪比的错误概念是()

    • A、适当延长TR后使信号增强
    • B、TE愈长,T2信号愈弱,SNR越低
    • C、TI增加,SNR也增大
    • D、表面线圈比体线圈SNR高
    • E、场强越高信噪比越低

    正确答案:E

  • 第4题:

    What is an advantage of an externally modulated laser over a directly modulated laser?()

    • A、lower cost
    • B、higher chirp
    • C、easier to manufacture
    • D、higher dispersion tolerance
    • E、higher optical signal-to-noise ratio

    正确答案:D

  • 第5题:

    信噪比测试中一般要求SNR大于().


    正确答案:70DB

  • 第6题:

    Which signal and noise values will result in the best phone communication with an access point?()

    • A、 Signal strength 0dBm, noise level 6dBm
    • B、 Signal strength 8dBm, noise level 9dBm
    • C、 Signal strength 4 dBm, noise level 4 dBm
    • D、 Signal strength 6dBm, noise level 5 dBm

    正确答案:A

  • 第7题:

    Which signal and noise values will result in the best phone communication with an access point?()

    • A、signal strength 46dBm, noise level 95dBm
    • B、signal strength 74dBm, noise level 94dBm
    • C、signal strength 68dBm, noise level 79dBm
    • D、signal strength 50dBm, noise level 56dBm

    正确答案:A

  • 第8题:

    单选题
    信噪比的错误概念是()
    A

    适当延长TR后使信号增强

    B

    TE愈长,T2信号愈弱,SNR越低

    C

    TI增加,SNR也增大

    D

    表面线圈比体线圈SNR高

    E

    场强越高信噪比越低


    正确答案: E
    解析: 图像的信噪比随场强下降但并不完全是线性的关系。

  • 第9题:

    单选题
    In the OSNR model for EDFA amplifiers, SNR OUT = 1/(1/SNR IN + FhvB/P IN ),  what does SNR IN represent?()
    A

     the signal to noise of the current optical amplifier

    B

     the signal to noise of the previous amplifier or source

    C

     the signal to noise introduced by the optical multiplexer

    D

     the accumulated noise to signal ratio of the optical channel


    正确答案: D
    解析: 暂无解析

  • 第10题:

    单选题
    Which of these terms refers to call issues that cause variations in timing or time of arrival?()
    A

    queuing

    B

    jitter

    C

    packet loss

    D

    digitized sampling

    E

    signal-to-noise ratio ratio


    正确答案: D
    解析: 暂无解析

  • 第11题:

    单选题
    In the OSNR model for EDFA amplifiers, SNR OUT = 1/(1/SNR IN + FhvB/P IN ), what does SNR IN represent?()
    A

    the signal to noise of the current optical amplifier

    B

    the signal to noise of the previous amplifier or source

    C

    the signal to noise introduced by the optical multiplexer

    D

    the accumulated noise to signal ratio of the optical channel


    正确答案: A
    解析: 暂无解析

  • 第12题:

    单选题
    What is an advantage of an externally modulated laser over a directly modulated laser? ()
    A

     lower cost

    B

     higher chirp

    C

     easier to manufacture

    D

     higher dispersion tolerance

    E

     higher optical signal-to-noise ratio


    正确答案: D
    解析: 暂无解析

  • 第13题:

    You are the Cisco Network Designer in Cisco.com. Which signal and noise values will result in the best phone communication with an access point?()

    A. signal strength 5dBm

    B. signal strength 6dBm

    C. noise level 4dBm

    D. noise level 5dBm


    参考答案:B, D

  • 第14题:

    Which of these terms refers to call issues that cause variations in timing or time of arrival?()

    • A、queuing
    • B、jitter
    • C、packet loss
    • D、digitized sampling
    • E、signal-to-noise ratio ratio

    正确答案:B

  • 第15题:

    In the OSNR model for EDFA amplifiers, SNR OUT = 1/(1/SNR IN + FhvB/P IN ), what does SNR IN represent?()

    • A、the signal to noise of the current optical amplifier
    • B、the signal to noise of the previous amplifier or source
    • C、the signal to noise introduced by the optical multiplexer
    • D、the accumulated noise to signal ratio of the optical channel

    正确答案:B

  • 第16题:

    OSNR英文全称Optical Signal-Noise Ratio,中文释义()。


    正确答案:光信噪比

  • 第17题:

    什么是RSRP?()

    • A、The received power on the resource elements that carry cell-specific reference signals
    • B、wideband power 
    • C、N times the Reference Signal Received Power divided by the total received power in the channel bandwidth 
    • D、Signal to Interference plus Noise Ratio

    正确答案:A

  • 第18题:

    As an experienced technician, you are responsible for Technical Support. A customer calls to ask the best signal level and noise level for cell phone. How to respond?()

    • A、-40dBm signal and -90dBm noise
    • B、-50dBm signal and -90dBm noise
    • C、-30dBm signal and -90dBm noise
    • D、-20dBm signal and -90dBm noise

    正确答案:A

  • 第19题:

    You are the Cisco Network Designer in Cisco.com. Which signal and noise values will result in thebest phone communication with an access point?()

    • A、 signal strength 5dBm
    • B、 signal strength 6dBm
    • C、 noise level 4dBm
    • D、 noise level 5dBm

    正确答案:B,D

  • 第20题:

    单选题
    What is an advantage of an externally modulated laser over a directly modulated laser?()
    A

    lower cost

    B

    higher chirp

    C

    easier to manufacture

    D

    higher dispersion tolerance

    E

    higher optical signal-to-noise ratio


    正确答案: E
    解析: 暂无解析

  • 第21题:

    单选题
    什么是RSRP?()
    A

    The received power on the resource elements that carry cell-specific reference signals

    B

    wideband power 

    C

    N times the Reference Signal Received Power divided by the total received power in the channel bandwidth 

    D

    Signal to Interference plus Noise Ratio


    正确答案: A
    解析: 暂无解析

  • 第22题:

    单选题
    As an experienced technician, you are responsible for Technical Support. A customer calls to askthe best signal level and noise level for cell phone. How to respond?()
    A

     -40dBm signal and -90dBm noise

    B

     -50dBm signal and -90dBm noise

    C

     -30dBm signal and -90dBm noise

    D

     -20dBm signal and -90dBm noise


    正确答案: B
    解析: 暂无解析

  • 第23题:

    单选题
    信噪比(signal to noise ratio,SNR)是MRI最基本的质量参数,其正确的概念表述应为()
    A

    图像的亮度与暗度之比 

    B

    两个像素的信号强度之比 

    C

    两个体素的信号强度之比 

    D

    图像的信号强度与背景强度之比 

    E

    图像的信号与噪声之比


    正确答案: D
    解析: 信噪比,英文名称叫做SNR或S/N(SIGNAL-NOISE RATIO),又称为讯噪比。是指一个电子设备或者电子系统中信号与噪声的比例。这里面的信号指的是来自设备外部需要通过这台设备进行处理的电子信号,噪声是指经过该设备后产生的原信号中并不存在的无规则的额外信号(或信息),并且该种信号并不随原信号的变化而变化。