Standard cell placement algorithms have been at the forefront of academic research concerning the physical design stages of VLSI design flows. The penultimate step of a standard cell placement procedure is legalizatio...Standard cell placement algorithms have been at the forefront of academic research concerning the physical design stages of VLSI design flows. The penultimate step of a standard cell placement procedure is legalization. In this step the manufacturability of the design is directly settled, and the quality of the solution, in terms of wirelength, congestion, timing and power consumption is indirectly defined. Since the heavy lifting regarding processing is performed by global placers, fast legalization solutions are protruded in state-of-the-art design flows. In this paper we propose and evaluate a legalization scheme that surpasses in execution speed two of the most widely used legalizers, without not only corrupting the quality of the final solution in terms of interconnection wirelength but improving it in the process.展开更多
This paper presents a method of designing a 65 nm DFM standard cell library.By reducing the amount of the library largely,the process of optical proximity correction（OPC） becomes more efficient and the need for larg...This paper presents a method of designing a 65 nm DFM standard cell library.By reducing the amount of the library largely,the process of optical proximity correction（OPC） becomes more efficient and the need for large storage is reduced.This library is more manufacture-friendly as each cell has been optimized according to the DFM rule and optical simulation.The area penalty is minor compared with traditional library,and the timing,as well as power has a good performance.Furthermore,this library has passed the test from the Technology Design Department of Foundry.The result shows this DFM standard cell library has advantages that improve the yield.展开更多
With shrinking transistor feature size,the fin-type field-effect transistor（FinFET） has become the most promising option in low-power circuit design due to its superior capability to suppress leakage.To support the ...With shrinking transistor feature size,the fin-type field-effect transistor（FinFET） has become the most promising option in low-power circuit design due to its superior capability to suppress leakage.To support the VLSI digital system flow based on logic synthesis,we have designed an optimized high-performance low-power FinFET standard cell library based on employing the mixed FBB/RBB technique in the existing stacked structure of each cell.This paper presents the reliability evaluation of the optimized cells under process and operating environment variations based on Monte Carlo analysis.The variations are modelled with Gaussian distribution of the device parameters and 10000 sweeps are conducted in the simulation to obtain the statistical properties of the worst-case delay and input-dependent leakage for each cell.For comparison,a set of non-optimal cells that adopt the same topology without employing the mixed biasing technique is also generated.Experimental results show that the optimized cells achieve standard deviation reduction of 39.1%and 30.7%at most in worst-case delay and inputdependent leakage respectively while the normalized deviation shrinking in worst-case delay and input-dependent leakage canbe up to 98.37%and 24.13%,respectively,which demonstrates that our optimized cells are less sensitive to variability and exhibit more reliability.展开更多
This paper introduces a novel standard-cell flash architecture for implementing analog-to-digital converters (ADC). The proposed ADC consists of several CMOS inverters all having their inputs connected to a common inp...This paper introduces a novel standard-cell flash architecture for implementing analog-to-digital converters (ADC). The proposed ADC consists of several CMOS inverters all having their inputs connected to a common input node. The out-put of the ADC is a thermometer code generated by the inverter outputs. Depending on the relationship between the input signal and a given inverter’s threshold voltage, the output will either be ‘0’ or ‘1’. By having many inverters with different threshold voltages, it is possible to create a 3-bit flash ADC. Even though the system is inherently non-linear, mathematical optimization has been done in order to improve its linearity. The proposed circuit dissipates 6.7 mW and uses in total 672 transistors of PMOS and NMOS types. This ADC is designed and simulated using TSMC’s 0.18 μm CMOS and results show that the proposed circuit works as expected even in presence of process variations.展开更多
China’s first general standard for stem cells officially released on November 22,2017 is expected to lay a foundation for regulating the application of stem cells technology.Stem cells are a group of self-renewal cel...China’s first general standard for stem cells officially released on November 22,2017 is expected to lay a foundation for regulating the application of stem cells technology.Stem cells are a group of self-renewal cells that can differentiate into specialized cells.They are now used for the treatment of many diseases.Despite a series of documents for regulating basic research and achievement transformation of stem cells,the clinical application and industrialization still face great challenges due to展开更多
Objective： Diffuse large B-cell lymphoma （DLBCL） is a heterogeneous disease. The prognostic factor currently used is not accurate enough to predict the outcomes of patients with DLBCL. The prognostic significance o...Objective： Diffuse large B-cell lymphoma （DLBCL） is a heterogeneous disease. The prognostic factor currently used is not accurate enough to predict the outcomes of patients with DLBCL. The prognostic significance of interim PET/CT in DLBCL remains controversial. The aim of this study is to determine the predictive value of interim 18F-FDG PET/CT after first-line treatment in patients with DLBCL. Methods： Thirty-two patients with DLBCL underwent baseline, interim and post-treatment lSF-FDG PET/CT scans. Imaging results were analyzed for the survival of patients via software SPSS 13.0, retrospectively. Results： Thirty-one of the 32 patients were treated with R-CHOP regimen, and interim 18F-FDG PET/CT of 24 patients was performed after 2 cycles of treatment. After a median follow-up period of 16.7 months, the 2-year progression-free survival （PFS） rates were significantly different between the groups above and below SUVmax CUt-Off value of 2.5 （P=0.039）. No significant differences were found in the 2-year PFS rates if SUVm, cut-offvalues were set as 2.0 and 3.0, respectively （P=0.360; P=0.113）. Conclusions： Interim PET/CT could predict the prognosis of DLBCL patients with the SUVmax cut-off value of 2.5, but more clinical data should be concluded to confirm this conclusion.展开更多
To detect the prognostic significance of interim F-FDG PET/CT SUV(standard uptake value) reduction(△SUV_(max)) associated with Ki67 in patients with diffuse large B cell lymphoma(DLBCL).47 DLBCL patients underwent PE...To detect the prognostic significance of interim F-FDG PET/CT SUV(standard uptake value) reduction(△SUV_(max)) associated with Ki67 in patients with diffuse large B cell lymphoma(DLBCL).47 DLBCL patients underwent PET/CT before initiation and after 2-4 cycles of chemotherapy were included.The SUV_(max)of the dominant lesions were calculated.Ki67 positive indices were provided by enzyme-labeled immunohistochemistry.SPSS17.0 was used for statistical analysis.ASUV_(max) of different groups were compared by t test.Receiver-operator characteristic analysis was performed to determine the optimal cutoff values.KaplanMeier analyses of PFS(Progression-free survival) were compared using log-rank test.The average of △SUV_(max)and △SUV_(max)%were 11.53 and 69.10%,respectively.The optimal cutoff values of △SUV_(max)x and △SUV_(max)%were 11.45 and 82.92%,respectively.Higher △SUV_(max) and △SUV_(max)%indicated longer PFS(p < 0.001).The optimal cutoff value of Ki67 was 55%.Ki67>55%was revealed to be an indicator of shorter PFS(p = 0.019).Either △SUV_(max)≤11.45 or Ki67>55%was defined as an indicator to poor outcome and scored 1 point.The PFS rate was 100%in patients scored 0 point,yet 0%in patients scored 2 points.PFS tended to be shorter along with the score getting higher(p = 0.006).△SUV_(max) and Ki67 positive index were both of significance in DLBCL prognosis.The prognostic value may be confirmed when △SUV_(max) was accordant with Ki67.展开更多
文摘Standard cell placement algorithms have been at the forefront of academic research concerning the physical design stages of VLSI design flows. The penultimate step of a standard cell placement procedure is legalization. In this step the manufacturability of the design is directly settled, and the quality of the solution, in terms of wirelength, congestion, timing and power consumption is indirectly defined. Since the heavy lifting regarding processing is performed by global placers, fast legalization solutions are protruded in state-of-the-art design flows. In this paper we propose and evaluate a legalization scheme that surpasses in execution speed two of the most widely used legalizers, without not only corrupting the quality of the final solution in terms of interconnection wirelength but improving it in the process.
基金supported by the National Major Specialized Program of China(Nos.2008ZX01035-001-07,2009ZX02023-4-2)
文摘This paper presents a method of designing a 65 nm DFM standard cell library.By reducing the amount of the library largely,the process of optical proximity correction（OPC） becomes more efficient and the need for large storage is reduced.This library is more manufacture-friendly as each cell has been optimized according to the DFM rule and optical simulation.The area penalty is minor compared with traditional library,and the timing,as well as power has a good performance.Furthermore,this library has passed the test from the Technology Design Department of Foundry.The result shows this DFM standard cell library has advantages that improve the yield.
基金Project supported by the National Natural Science Foundation of China(No.61306040)the State Key Development Program for Basic Research of China(No.2015CB057201)+1 种基金the Beijing Natural Science Foundation(No.4152020)Natural Science Foundation of Guangdong Province,China(No.2015A030313147)
文摘With shrinking transistor feature size,the fin-type field-effect transistor（FinFET） has become the most promising option in low-power circuit design due to its superior capability to suppress leakage.To support the VLSI digital system flow based on logic synthesis,we have designed an optimized high-performance low-power FinFET standard cell library based on employing the mixed FBB/RBB technique in the existing stacked structure of each cell.This paper presents the reliability evaluation of the optimized cells under process and operating environment variations based on Monte Carlo analysis.The variations are modelled with Gaussian distribution of the device parameters and 10000 sweeps are conducted in the simulation to obtain the statistical properties of the worst-case delay and input-dependent leakage for each cell.For comparison,a set of non-optimal cells that adopt the same topology without employing the mixed biasing technique is also generated.Experimental results show that the optimized cells achieve standard deviation reduction of 39.1%and 30.7%at most in worst-case delay and inputdependent leakage respectively while the normalized deviation shrinking in worst-case delay and input-dependent leakage canbe up to 98.37%and 24.13%,respectively,which demonstrates that our optimized cells are less sensitive to variability and exhibit more reliability.
文摘This paper introduces a novel standard-cell flash architecture for implementing analog-to-digital converters (ADC). The proposed ADC consists of several CMOS inverters all having their inputs connected to a common input node. The out-put of the ADC is a thermometer code generated by the inverter outputs. Depending on the relationship between the input signal and a given inverter’s threshold voltage, the output will either be ‘0’ or ‘1’. By having many inverters with different threshold voltages, it is possible to create a 3-bit flash ADC. Even though the system is inherently non-linear, mathematical optimization has been done in order to improve its linearity. The proposed circuit dissipates 6.7 mW and uses in total 672 transistors of PMOS and NMOS types. This ADC is designed and simulated using TSMC’s 0.18 μm CMOS and results show that the proposed circuit works as expected even in presence of process variations.
文摘China’s first general standard for stem cells officially released on November 22,2017 is expected to lay a foundation for regulating the application of stem cells technology.Stem cells are a group of self-renewal cells that can differentiate into specialized cells.They are now used for the treatment of many diseases.Despite a series of documents for regulating basic research and achievement transformation of stem cells,the clinical application and industrialization still face great challenges due to
文摘Objective： Diffuse large B-cell lymphoma （DLBCL） is a heterogeneous disease. The prognostic factor currently used is not accurate enough to predict the outcomes of patients with DLBCL. The prognostic significance of interim PET/CT in DLBCL remains controversial. The aim of this study is to determine the predictive value of interim 18F-FDG PET/CT after first-line treatment in patients with DLBCL. Methods： Thirty-two patients with DLBCL underwent baseline, interim and post-treatment lSF-FDG PET/CT scans. Imaging results were analyzed for the survival of patients via software SPSS 13.0, retrospectively. Results： Thirty-one of the 32 patients were treated with R-CHOP regimen, and interim 18F-FDG PET/CT of 24 patients was performed after 2 cycles of treatment. After a median follow-up period of 16.7 months, the 2-year progression-free survival （PFS） rates were significantly different between the groups above and below SUVmax CUt-Off value of 2.5 （P=0.039）. No significant differences were found in the 2-year PFS rates if SUVm, cut-offvalues were set as 2.0 and 3.0, respectively （P=0.360; P=0.113）. Conclusions： Interim PET/CT could predict the prognosis of DLBCL patients with the SUVmax cut-off value of 2.5, but more clinical data should be concluded to confirm this conclusion.
文摘To detect the prognostic significance of interim F-FDG PET/CT SUV(standard uptake value) reduction(△SUV_(max)) associated with Ki67 in patients with diffuse large B cell lymphoma(DLBCL).47 DLBCL patients underwent PET/CT before initiation and after 2-4 cycles of chemotherapy were included.The SUV_(max)of the dominant lesions were calculated.Ki67 positive indices were provided by enzyme-labeled immunohistochemistry.SPSS17.0 was used for statistical analysis.ASUV_(max) of different groups were compared by t test.Receiver-operator characteristic analysis was performed to determine the optimal cutoff values.KaplanMeier analyses of PFS(Progression-free survival) were compared using log-rank test.The average of △SUV_(max)and △SUV_(max)%were 11.53 and 69.10%,respectively.The optimal cutoff values of △SUV_(max)x and △SUV_(max)%were 11.45 and 82.92%,respectively.Higher △SUV_(max) and △SUV_(max)%indicated longer PFS(p < 0.001).The optimal cutoff value of Ki67 was 55%.Ki67>55%was revealed to be an indicator of shorter PFS(p = 0.019).Either △SUV_(max)≤11.45 or Ki67>55%was defined as an indicator to poor outcome and scored 1 point.The PFS rate was 100%in patients scored 0 point,yet 0%in patients scored 2 points.PFS tended to be shorter along with the score getting higher(p = 0.006).△SUV_(max) and Ki67 positive index were both of significance in DLBCL prognosis.The prognostic value may be confirmed when △SUV_(max) was accordant with Ki67.
