Global Unichip (Taiwan)

As CMOS technology scales down, the number of standard cells increases rapidly. The increasing cell count raises the complexity of physical design. Routing is one of the most time-consuming stages in the physical design flow. When routing fails to meet design rules or performance targets, designers must revise earlier stages such as floorplanning or placement. Repeating the routing process causes high design cost and long time-to-market. Early prediction of routing demand helps reduce design iterations. An ensemble learning model based on XGBoost is proposed to predict global routing demand using placement-stage features. The XGBoost-based model achieves higher accuracy than CNN- and FCN-based models, improving R² by 0.12 and 0.125, respectively. The inference speed is also significantly faster, up to 14.95×. Feature importance analysis enables reduction of training and inference overhead with minimal accuracy loss.

Stellar parameters and magnetic activity are important for the understanding of stellar physics and dynamo theory. We have used LAMOST spectroscopic surveys to study stellar parameters and magnetic activity properties of TESS objects. There are 46,684 spectra of 31,385 TESS objects in the LAMOST low-resolution spectral survey. We have calculated equivalent widths of Ca ii H and K, and Hα lines, and discussed the relationship of chromospheric activity with stellar temperature. There are 25,710 spectra of 10,404 stars with repeated low-resolution observations. We found that there are 694 objects with variations of the Hα line and 1406 objects with varying radial velocities. Moreover, there are 14,099 spectra of 5834 TESS objects in the LAMOST medium-resolution survey, of which there are 2666 objects with Hα variations and 1480 objects with variation in radial velocities. By using the light curves of the TESS objects in the LAMOST field, we detected 4269 flare events and determined their flare parameters. We have confirmed that the fraction of the flare stars increases as stellar temperature decreases. There is also an observed relationship between the flare energy and chromospheric activity. We have calculated the power-law index between the flare energy and decay time using TESS data to be 0.27(0.01), which can be explained by the magnetic reconnection theory. We confirmed that is stable for Rossby number R < 0.1 and decreases with the increase of Rossby number R > 0.1. There is a positive correlation between the brightness variation amplitude due to star spots from TESS and the Hα intensity from LAMOST.

Even though routability is of great concern to a recent global placement algorithm, there still exists a large room to improve it. To make legalization more easier and get a better placement, this article proposes an iterative approach to refine cell locations after global placement, where wirelength and routability are separately optimized in each iteration. It first moves cells to better locations to reduce wirelength. Unlike previous approaches, our approach guarantees that no wirelength will be increased so that the previous optimization result can be better maintained. Moreover, we propose a delicate procedure to move cells according to their gain values to reduce the largest wirelength. Next, the whitespace re-allocation approach is applied to redistribute whitespace over a chip to improve routability without changing relative locations of cells. To ensure that enough space will be allocated to the most routing congestion regions, we propose a sigmoid function to increase routing demands of regions according to their routing overflows and number of pins. The experimental results show that our methodology can obtain shorter wirelength and better routability in industrial designs when compared to other approach.

protein and gff

Somatic symptoms are prevalent in patients with depression. The centromedial amygdala (CMA) is a key brain region that mediates autonomic and somatic responses. Abnormal function in the CMA may contribute to the development of somatic symptoms in depressed patients. We compared the resting-state functional connectivity (RSFC) based on the seed of the left and right CMA between 37 patients with depression and 30 healthy controls. The severity of depressive and somatic symptoms was assessed using the Hamilton Depression Rating Scale (HDRS) and the 15-item somatic symptom severity scale of the Patient Health Questionnaire (PHQ-15). Correlation analysis was performed to investigate the relationship between the RSFC and clinical variables (HDRS and PHQ-15) in depressed patients. Compared with healthy controls, patients with depression exhibited decreased RSFC between the CMA and insula, and superior temporal gyrus. In addition, functional connectivity between the left CMA and left insula was negatively correlated with PHQ-15 (r = -0.348, p = .037) in depressed patients. No significant relation was found between the RSFC and HDRS in depressed patients. Functional connectivity between the CMA and insula is reduced in depressive patients, which is associated with the severity of somatic symptoms. Our findings may provide a potential neural substrate to interpret the co-occurrence of depression with somatic symptoms.

In recent years, as the progress of VLSI technology, artificial intelligence / deep learning has become a major trend. To satisfy the demand of high performance computing, many AI ASICs adopt multi-core architecture. The challenges for clocking of this architecture consists of timing closure issues and the implementation of low latency, low skew and low OCV top-level clock tree for highspeed operation (> 1GHz). In this paper, we share our experiences on clock tree synthesis of HPC ASICs. Two different clocking strategies are introduced including H-tree planning with customized big drivers and clock mesh.

The objective of this study is to recover SiC from silicon wafer cutting slurry using physical separation and acid/alkali purification processes. Hydrocyclone was used in the first-stage process to recover SiC and Si from silicon wafer cutting slurry. Through hydrocyclone separation, the SiC content and recovery of can reach 98 and 88%, respectively. In acid and alkali purification processes, the iron and silicon can be removed and further increase the SiC content up to 99.5%. From the test results obtained in this study, it is believed that the recycling and reutilization of SiC from silicon wafer cutting slurry can be highly feasible and economical.

Clock gating is recognized as one of the most effective techniques to reduce the dynamic power consumption. Many research efforts have been paid to build activity-driven clock trees for low power designs. On the other hand, as the feature size continues to shrink, the on-chip-variation (OCV) effect has become a serious concern, especially for the clock skew of the top-level clock tree. Based on this observation, in this paper, we present the first work for the synthesis of OCV-aware top-level activity-driven clock trees. In our approach, the clock skew variation is considered during the top-level activity-driven clock tree synthesis. Our objective is to minimize the weighted sum of the worst timing slack and the power consumption. Compared with previous works, benchmark data consistently show that our approach can greatly increase the worst timing slack with a small overhead on the power consumption.