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Low-Power Techniques for Network-on-Chip
Published in Santanu Kundu, Santanu Chattopadhyay, Network-on-Chip, 2018
Santanu Kundu, Santanu Chattopadhyay
The operation of the new level converter circuit is explained here. When the voltage level of the input signal swings high to low, the output voltage level of the input inverter becomes the lower supply voltage VDDL. Therefore, MN2, MN5, and MP6 are turned on. As a result, node A is then discharged to a reference voltage VSS. Thus, MP3 becomes on, and then the voltage level of node B becomes a higher supply voltage VDDH. In this case, MP2, MN3, MN6, and MP5 are turned off, and therefore, it is possible to prevent a short-circuit current from flowing between the higher power supply voltage VDDH and the reference voltage VSS. However, when the voltage level of the input signal is switched to logic high, the output voltage level of the input inverter becomes a reference voltage VSS. Therefore, MN3, MN6, and MP5 are turned on. As a result, node B is then discharged to a reference voltage VSS. In this case, MP2 is turned on, and therefore, MP3 becomes off. Moreover, MN2, MN5, and MP6 are also turned off, and thus, it is possible to prevent a short-circuit current from flowing between the higher power supply voltage VDDH and the reference voltage VSS. It is clear that there are three paths to speed up the output level transition in each input signal condition. These results provide faster output transitions as well as an efficient voltage level conversion. As such, it can reduce the contention problem on nodes A and B. As a result, the propagation delay time of the circuit itself becomes short. Moreover, no short-circuit current flows; therefore, it is possible to reduce power consumption.
Audio Codecs
Published in Francis F. Li, Trevor J. Cox, Digital Signal Processing in Audio and Acoustical Engineering, 2019
MPEG-1 audio layer I (MP1) is generally obsolete, and replaced by MPEG-I layers II (MP2) and III (MP3). MP2 is currently a main-stream format for digital audio broadcasting due to its relatively simple decoding requirements. MP3 is a popular format for personal audio. The MP3 was instigated by Thomson Multimedia and the Fraunhofer Institute, and then got adopted by the MPEG. Like many other MPEG standards, not every single aspect of the MP3 codecs is specified. Different implementations are possible. Therefore, there are several different but generally compatible implementations.
Predicting the Performance of Outdoor Noise Barriers
Published in Keith Attenborough, Timothy Van Renterghem, Predicting Outdoor Sound, 2021
Keith Attenborough, Timothy Van Renterghem
At microphone positions MP1, MP2 and MP3 and at frequencies below 1 kHz, the gabions provide less than 5 dB insertion loss. Above about 1 kHz, the shielding strongly increases up to 25 dB in the considered frequency range. Although MP1 and MP2 were positioned symmetrically relative to the source and barrier, they show rather different insertion loss spectra which may be the result of non-uniform filling of stones in the cages, non-symmetric positioning of the poles and potentially small microphone positioning errors. Note that the empty container has a non-negligible influence on the insertion loss since the poles and the U-profile partly shield and scatter sound. When the gabion barriers were formed from porous lava stones rather than rigid non-porous stones, the shielding is enhanced particularly above 1 kHz. Also, when the gabion stones were porous, increasing the gabion thickness from 0.2 to 0.3 m leads to higher sound shielding over a wide frequency range, even though stones within the 30-cm thick barrier were piled to a lower height. This means that larger thickness seems to be more important for the shielding than small differences in the height of the stone filling. The insertion losses at microphone position MP4 on the same side as the source due to the empty cage and poles are close to zero but slightly negative when the gabion cage is filled with stones, from which one can conclude that the stones are mainly responsible for reflections coming from the gabion. Differences in the gabion height and width do not influence these reflections significantly.
A Novel Method to Apply Reliability-Centered Maintenance on Over-Current Protection Systems
Published in Electric Power Components and Systems, 2020
Mohammad Hossein Nasri, Sayed Yaser Derakhshandeh, Abbas Kargar
As seen in Table 4, the current maintenance plan used in this system is TBM in which has no maintenance task for CT and DC terminals. Thus, it is expected that the optimum plan obtained from the proposed RCM method could evidently improve the reliability. The superiority of all Pareto points shown in Figure 4(b) in compared to the current plan is an obvious reason for this claim. Considering the results provided in Table 4 (columns CMP and MP1), the proposed method could present a maintenance plan with an approximate cost of current plan and twice better reliability. Additionally, the MP2 indicates a maintenance plan with almost similar reliability of the current maintenance plan with an annual cost reduction by 24%. Finally, the best proposed plan and its modified version highly improve both the reliability and cost in comparison with CMP.