AIM:To identify the determinants of endoscopic submucosal dissection(ESD) operation time.METHODS:This investigation was conducted as a single-center,prospective study in which ESD was performed by the same endoscopist...AIM:To identify the determinants of endoscopic submucosal dissection(ESD) operation time.METHODS:This investigation was conducted as a single-center,prospective study in which ESD was performed by the same endoscopist at the Chinese PLA General Hospital.A total of 173 patients underwent ESD operations performed by Dr.Lu from July 2007 to December 2011,and 183 lesions were enrolled.Patient gender,age,tumor location,gross type,tumor size,pathological type and adhesions were recorded prospectively.The order of treatment represented the experience of the operator.Univariate analysis and multivariate analysis were performed to evaluate the relationships between these factors and ESD procedure time.RESULTS:Univariate analysis showed the ESD time was closely related to the gender(P = 0.0210),tumor size(P < 0.0001),location(P < 0.0001),gross type(P < 0.0001) and adhesion(P = 0.0010).The surgical proficiency level was associated with ESD time in unit area(P < 0.0001).Multivariate analysis revealed that the ESD time was positively correlated with tumor size(P < 0.0001),adhesion(P < 0.0001) and location(P < 0.0001),but negatively correlated with surgical proficiency level(P = 0.0046).CONCLUSION:Large tumor size,adjacency to the cardia,and adhesion are predictors of a long ESD time,whereas high surgical proficiency level predicts a short ESD time.展开更多
AIM To investigate the hypothesis that exposure to guanidinoacetate(GAA, a potent methyl-group consumer) either alone or combined with ethanol intake for a prolonged period of time would cause more advanced liver path...AIM To investigate the hypothesis that exposure to guanidinoacetate(GAA, a potent methyl-group consumer) either alone or combined with ethanol intake for a prolonged period of time would cause more advanced liver pathology thus identifying methylation defects as the initiator and stimulator for progressive liver damage.METHODS Adult male Wistar rats were fed the control or ethanolLieber De Carli diet in the absence or presence of GAA supplementation. At the end of 6 wk of the feeding regimen, various biochemical and histological analyses were conducted. RESULTS Contrary to our expectations, we observed that GAA treatment alone resulted in a histologically normal liver without evidence of hepatosteatosis despite persistence of some abnormal biochemical parameters. This protection could result from the generation of creatine from the ingested GAA. Ethanol treatment for 6 wk exhibited changes in liver methionine metabolism and persistence of histological and biochemical defects as reported before. Further, when the rats were fed the GAA-supplemented ethanol diet, similar histological and biochemical changes as observed after 2 wk of combined treatment, including inflammation, macroand micro-vesicular steatosis and a marked decrease in the methylation index were noted. In addition, rats on the combined treatment exhibited increased liver toxicity and even early fibrotic changes in a subset of animals in this group. The worsening liver pathology could be related to the profound reduction in the hepatic methylation index, an increased accumulation of GAA and the inability of creatine generated to exert its hepato-protective effects in the setting of ethanol.CONCLUSION To conclude, prolonged exposure to a methyl consumer superimposed on chronic ethanol consumption causes persistent and pronounced liver damage.展开更多
Objectives To investigate the associations of the plasma homocysteine levels with the alterations in arterial stiffness in a commu- nity-based cohort. The gender differences in these associations were examined. Method...Objectives To investigate the associations of the plasma homocysteine levels with the alterations in arterial stiffness in a commu- nity-based cohort. The gender differences in these associations were examined. Methods We evaluated the relationship between plasma homocysteine levels to three measures of vascular ftmction [carotid-femoral pulse wave velocity （CF-PWV）, carotid-ankle PWV （CA-PWV） and heart rate corrected augmentation index （AI）] in 1680 participants （mean age： 61.5 years; 709 men, 971 women） from communities of Beijing, China. Results In univariate analysis, plasma homocysteine levels was positively related to the CF-PWV （r = 0.211, P 〈 0.0001） and CA-PWV （r = 0.148, P 〈 0.0001）, whereas inversely associated with AI （r = -0.052, P = 0.016）. In multiple linear regression models adjusting for covariants, plasma homocysteine remained positively related to the CF-PWV （standardized 13 = 0.065, P = 0.007） in total cases. When the groups of men and women were examined separately, plasma homocysteine remained positively associated with the CF-PWV （standardized β = 0.082, P = 0.023） in men, whereas the relations between homocysteine and any of the arterial stiffness indices were not further present in women. Conclusions In Chinese population, plasma homocysteine levels are independently associated with alterations of large artery stiffness in men but not in women.展开更多
In this paper, we study the rank of matrices over GF(2~p),and propose two construction methods for algebraic-based nonbinary LDPC codes from an existing LDPC code, referred to as the original code. By multiplying all ...In this paper, we study the rank of matrices over GF(2~p),and propose two construction methods for algebraic-based nonbinary LDPC codes from an existing LDPC code, referred to as the original code. By multiplying all elements of each column of the binary parity-check matrix H corresponding to the original code with the same nonzero element of any field, the first class of nonbinary LDPC codes with flexible field order is proposed. The second method is to replace the nonzero elements of some columns in H with different nonzero field elements in a given field, and then another class of nonbinary LDPC codes with various rates is obtained. Simulation results show that the proposed nonbinary LDPC codes perform well over the AWGN channel with the iterative decoding algorithms.展开更多
Abiotic stresses such as drought, salinity, and low temperature cause–losses in rice production worldwide. The emergence of transgenic technology has enabled improvements in the drought resistance of rice plants and ...Abiotic stresses such as drought, salinity, and low temperature cause–losses in rice production worldwide. The emergence of transgenic technology has enabled improvements in the drought resistance of rice plants and helped avert crop damage due to drought stress.Selectable marker genes conferring resistance to antibiotics or herbicides have been widely used to identify genetically modified plants. However, the use of such markers has limited the public acceptance of genetically modified organisms. Marker-free materials (i.e., those containing a single foreign gene) may be more easily accepted by the public and more likely to find common use. In the present study, we created marker-free drought-tolerant transgenic rice plants using particle bombardment. Overall, 842 T_0plants overexpressing the rice ascorbate peroxidase-coding gene OsAPX2 were generated. Eight independentmarker-free lines were identified from T_1 seedlings using the polymerase chain reaction.The molecular characteristics of these lines were examined, including the expression level,copy number, and flanking sequences of OsAPX2, in the T_2 progeny. A simulated drought test using polyethylene glycol and a drought-tolerance test of seedlings confirmed that the marker-free lines carrying OsAPX2 showed significantly improved drought tolerance in seedlings. In the field, the yield of the wild-type plant decreased by 60% under drought conditions compared with normal conditions. However, the transgenic line showed a yield loss of approximately 26%. The results demonstrated that marker-free transgenic lines significantly improved grain yield under drought-stressed conditions.展开更多
The girth plays an important role in the design of LDPC codes. In order to determine the girth of Tanner(5,7) quasi-cyclic( QC) LDPC codes with length 7p for p being a prime with the form 35 m + 1,the cycles of length...The girth plays an important role in the design of LDPC codes. In order to determine the girth of Tanner(5,7) quasi-cyclic( QC) LDPC codes with length 7p for p being a prime with the form 35 m + 1,the cycles of lengths 4,6,8,and 10 are analyzed. Then these cycles are classified into sixteen categories,each of which can be expressed as an ordered block sequence,or a certain type. It is also shown that the existence of these cycles is equal to polynomial equations over Fpwho has a 35th unit root. We check if these polynomial equations have a 35th unit root and obtain the girth values of Tanner(5,7) QC LDPC codes.展开更多
To carry out curriculum ideological and political education is to thoroughly implement the whole staff,the whole process,and all-round education.Taking the environmental chemistry course as an example,it introduces th...To carry out curriculum ideological and political education is to thoroughly implement the whole staff,the whole process,and all-round education.Taking the environmental chemistry course as an example,it introduces the feasibility of developing ideological and political education,and analyzes how to realize the integration of environmental chemistry courses and ideological and political education from the aspects of changing concepts,carefully designing teaching content,and playing the role of training courses and experimental courses.Integration has achieved certain results,providing reference and reference for environmental majors to carry out related courses ideological and political education.展开更多
To the Editor:Allogeneic hemopoietic stem cell transplantation(allo-HSCT)represents the only long-term survival treatment choice for patients with myelodysplastic syndromes(MDS)and MDS/myeloproliferative neoplasm(MPN)...To the Editor:Allogeneic hemopoietic stem cell transplantation(allo-HSCT)represents the only long-term survival treatment choice for patients with myelodysplastic syndromes(MDS)and MDS/myeloproliferative neoplasm(MPN).Unfortunately,post-hemopoietic stem cell transplantation(HSCT)relapse remains a cause of treatment failure and the results of salvage treatments are poor.Developing better conditioning regimens is urgently needed.Previous studies have shown synergistic antileukemic effects between decitabine(DEC)and idarubicin(IDA).[1]In an attempt to design a conditioning strategy with very low toxicity but considerable myelosuppressive activity and potential immune-enhancing effects for patients with high-risk MDS and MDS/MPN,we combined DEC and IDA with busulfan,cyclophosphamide,andudarabine for a modied myeloablative regimen in this prospective,multicenter cohort study(hereafter referred to as the“DEC/IDA study”).展开更多
In order to analyze and process the large graphs with high cost efficiency,researchers have developed a number of out-of-core graph processing systems in recent years based on just one commodity computer.On the other ...In order to analyze and process the large graphs with high cost efficiency,researchers have developed a number of out-of-core graph processing systems in recent years based on just one commodity computer.On the other hand,with the rapidly growing need of analyzing graphs in the real-world,graph processing systems have to efficiently handle massive concurrent graph processing(CGP)jobs.Unfortunately,due to the inherent design for single graph processing job,existing out-of-core graph processing systems usually incur unnecessary data accesses and severe competition of I/O bandwidth when handling the CGP jobs.In this paper,we propose GraphCP,a disk I/O optimized out-of-core graph processing system that efficiently supports the processing of CGP jobs.GraphCP proposes a benefit-aware sharing execution model to share the I/O access and processing of graph data among the CGP jobs and adaptively schedule the graph data loading based on the states of vertices,which efficiently overcomes above challenges faced by existing out-of-core graph processing systems.Moreover,GraphCP adopts a dependency-based future-vertex updating model so as to reduce disk I/Os in the future iterations.In addition,GraphCP organizes the graph data with a Source-Sorted Sub-Block graph representation for better processing capacity and I/O access locality.Extensive evaluation results show that GraphCP is 20.5×and 8.9×faster than two out-of-core graph processing systems GridGraph and GraphZ,and 3.5×and 1.7×faster than two state-of-art concurrent graph processing systems Seraph and GraphSO.展开更多
Resistive random access memory(RRAM)enables the functionality of operating massively parallel dot products and accumulations.RRAM-based accelerator is such an effective approach to bridging the gap between Internet of...Resistive random access memory(RRAM)enables the functionality of operating massively parallel dot products and accumulations.RRAM-based accelerator is such an effective approach to bridging the gap between Internet of Things devices’constrained resources and deep neural networks’tremendous cost.Due to the huge overhead of Analog to Digital(A/D)and digital accumulations,analog RRAM buffer is introduced to extend the processing in analog and in approximation.Although analog RRAM buffer offers potential solutions to A/D conversion issues,the energy consumption is still challenging in resource-constrained environments,especially with enormous intermediate data volume.Besides,critical concerns over endurance must also be resolved before the RRAM buffer could be frequently used in reality for DNN inference tasks.Then we propose LayCO,a layer-centric co-optimizing scheme to address the energy and endurance concerns altogether while strictly providing an inference accuracy guarantee.LayCO relies on two key ideas:1)co-optimizing with reduced supply voltage and reduced bit-width of accelerator architectures to increase the DNN’s error tolerance and achieve the accelerator’s energy efficiency,and 2)efficiently mapping and swapping individual DNN data to a corresponding RRAM partition in a way that meets the endurance requirements.The evaluation with representative DNN models demonstrates that LayCO outperforms the baseline RRAM buffer based accelerator by 27x improvement in energy efficiency(over TIMELY-like configuration),308x in lifetime prolongation and 6x in area reduction(over RAQ)while maintaining the DNN accuracy loss less than 1%.展开更多
A storage system is the core of a computer,and plays an important role in the sustainable development of emerging strategic industries,such as artificial intelligence,big data,cloud computing,and the Internet of Thing...A storage system is the core of a computer,and plays an important role in the sustainable development of emerging strategic industries,such as artificial intelligence,big data,cloud computing,and the Internet of Things.Storage stack access is a major factor restricting the performance of data-intensive systems because of the increasing performance of processors and network devices.展开更多
文摘目的探讨骨密度与胫骨平台骨折切开复位内固定(open reduction internal fixation,ORIF)术后患者临床结局的关系。方法回顾性选择2012年1月至2016年12月来我院接受ORIF术治疗的胫骨平台骨折患者100例,根据术后1年美国特种外科医院(the hospital special surgery,HSS)膝关节功能评分将入组患者分为HSS评分大于等于70分组(72例)和HSS评分小于70分组(28例)。收集所有入组患者的治疗及随访资料,包括性别、年龄、身体质量指数(body mass index,BMI)、吸烟史、嗜酒史、糖尿病史、高血压病史、高血脂病史、初始平台塌陷程度、术后并发症发生情况、术后复位情况等,比较两组患者在临床特征方面的差异。应用单因素、多因素非条件Logistic回归分析影响胫骨平台ORIF术后患者临床结局的危险性因素。结果两组患者在年龄、糖尿病史、Schatzker分型、初始平台塌陷程度、术后并发症、术后复位、骨密度T值方面比较差异有统计学意义(P<0.05),在性别、BMI、吸烟史、嗜酒史、高血压病史、高血脂病史、损伤原因方面比较差异无统计学意义(P>0.05)。单因素Logistic回归分析结果显示,年龄、糖尿病史、Schatzker分型、初始平台塌陷程度、术后并发症发生情况、术后复位情况、骨密度T值是影响胫骨平台ORIF术后患者临床结局的危险性因素(P<0.05)。将以上变量进行多因素Logistic回归分析结果显示,年龄大于等于60岁、有糖尿病史、Schatzker分型为Ⅳ~Ⅵ型、骨密度T值小于等于-1.0不利于胫骨平台ORIF术后患者临床结局(P<0.05)。结论骨密度与胫骨平台骨折ORIF术后患者临床结局密切相关,骨密度T值小于等于-1.0不利于胫骨平台ORIF术后患者临床结局。
文摘AIM:To identify the determinants of endoscopic submucosal dissection(ESD) operation time.METHODS:This investigation was conducted as a single-center,prospective study in which ESD was performed by the same endoscopist at the Chinese PLA General Hospital.A total of 173 patients underwent ESD operations performed by Dr.Lu from July 2007 to December 2011,and 183 lesions were enrolled.Patient gender,age,tumor location,gross type,tumor size,pathological type and adhesions were recorded prospectively.The order of treatment represented the experience of the operator.Univariate analysis and multivariate analysis were performed to evaluate the relationships between these factors and ESD procedure time.RESULTS:Univariate analysis showed the ESD time was closely related to the gender(P = 0.0210),tumor size(P < 0.0001),location(P < 0.0001),gross type(P < 0.0001) and adhesion(P = 0.0010).The surgical proficiency level was associated with ESD time in unit area(P < 0.0001).Multivariate analysis revealed that the ESD time was positively correlated with tumor size(P < 0.0001),adhesion(P < 0.0001) and location(P < 0.0001),but negatively correlated with surgical proficiency level(P = 0.0046).CONCLUSION:Large tumor size,adjacency to the cardia,and adhesion are predictors of a long ESD time,whereas high surgical proficiency level predicts a short ESD time.
基金Supported by a Merit Review grant BX001155(to Kharbanda KK)from the Department of Veterans Affairs,Office of Research and Development(Biomedical Laboratory Research and Development)
文摘AIM To investigate the hypothesis that exposure to guanidinoacetate(GAA, a potent methyl-group consumer) either alone or combined with ethanol intake for a prolonged period of time would cause more advanced liver pathology thus identifying methylation defects as the initiator and stimulator for progressive liver damage.METHODS Adult male Wistar rats were fed the control or ethanolLieber De Carli diet in the absence or presence of GAA supplementation. At the end of 6 wk of the feeding regimen, various biochemical and histological analyses were conducted. RESULTS Contrary to our expectations, we observed that GAA treatment alone resulted in a histologically normal liver without evidence of hepatosteatosis despite persistence of some abnormal biochemical parameters. This protection could result from the generation of creatine from the ingested GAA. Ethanol treatment for 6 wk exhibited changes in liver methionine metabolism and persistence of histological and biochemical defects as reported before. Further, when the rats were fed the GAA-supplemented ethanol diet, similar histological and biochemical changes as observed after 2 wk of combined treatment, including inflammation, macroand micro-vesicular steatosis and a marked decrease in the methylation index were noted. In addition, rats on the combined treatment exhibited increased liver toxicity and even early fibrotic changes in a subset of animals in this group. The worsening liver pathology could be related to the profound reduction in the hepatic methylation index, an increased accumulation of GAA and the inability of creatine generated to exert its hepato-protective effects in the setting of ethanol.CONCLUSION To conclude, prolonged exposure to a methyl consumer superimposed on chronic ethanol consumption causes persistent and pronounced liver damage.
基金This work was supported by grants from the Key National Basic Research Program of China （2012CB517503, 2013CB530804） and Nature Science Foundation of China （81270941） to Ye P, and the Nature Science Foundation of China （81100878） and the Beijing Nova Program （Z121107002513124） to Bai Y. The authors have no conflict of interest to declare.
文摘Objectives To investigate the associations of the plasma homocysteine levels with the alterations in arterial stiffness in a commu- nity-based cohort. The gender differences in these associations were examined. Methods We evaluated the relationship between plasma homocysteine levels to three measures of vascular ftmction [carotid-femoral pulse wave velocity （CF-PWV）, carotid-ankle PWV （CA-PWV） and heart rate corrected augmentation index （AI）] in 1680 participants （mean age： 61.5 years; 709 men, 971 women） from communities of Beijing, China. Results In univariate analysis, plasma homocysteine levels was positively related to the CF-PWV （r = 0.211, P 〈 0.0001） and CA-PWV （r = 0.148, P 〈 0.0001）, whereas inversely associated with AI （r = -0.052, P = 0.016）. In multiple linear regression models adjusting for covariants, plasma homocysteine remained positively related to the CF-PWV （standardized 13 = 0.065, P = 0.007） in total cases. When the groups of men and women were examined separately, plasma homocysteine remained positively associated with the CF-PWV （standardized β = 0.082, P = 0.023） in men, whereas the relations between homocysteine and any of the arterial stiffness indices were not further present in women. Conclusions In Chinese population, plasma homocysteine levels are independently associated with alterations of large artery stiffness in men but not in women.
基金supported in part by National Basic Research Program of China under Grant No.2012CB316100National Natural Science Foundation of China under Grants 61372074 and 91438101+1 种基金Joint Funds of the National Natural Science Foundation of China under Grant No.U1504601Science and Technology on Communication Networks Laboratory under Grant KX132600032
文摘In this paper, we study the rank of matrices over GF(2~p),and propose two construction methods for algebraic-based nonbinary LDPC codes from an existing LDPC code, referred to as the original code. By multiplying all elements of each column of the binary parity-check matrix H corresponding to the original code with the same nonzero element of any field, the first class of nonbinary LDPC codes with flexible field order is proposed. The second method is to replace the nonzero elements of some columns in H with different nonzero field elements in a given field, and then another class of nonbinary LDPC codes with various rates is obtained. Simulation results show that the proposed nonbinary LDPC codes perform well over the AWGN channel with the iterative decoding algorithms.
基金supported by the National Major Project for Developing New GM Crops (2016ZX08001-003)
文摘Abiotic stresses such as drought, salinity, and low temperature cause–losses in rice production worldwide. The emergence of transgenic technology has enabled improvements in the drought resistance of rice plants and helped avert crop damage due to drought stress.Selectable marker genes conferring resistance to antibiotics or herbicides have been widely used to identify genetically modified plants. However, the use of such markers has limited the public acceptance of genetically modified organisms. Marker-free materials (i.e., those containing a single foreign gene) may be more easily accepted by the public and more likely to find common use. In the present study, we created marker-free drought-tolerant transgenic rice plants using particle bombardment. Overall, 842 T_0plants overexpressing the rice ascorbate peroxidase-coding gene OsAPX2 were generated. Eight independentmarker-free lines were identified from T_1 seedlings using the polymerase chain reaction.The molecular characteristics of these lines were examined, including the expression level,copy number, and flanking sequences of OsAPX2, in the T_2 progeny. A simulated drought test using polyethylene glycol and a drought-tolerance test of seedlings confirmed that the marker-free lines carrying OsAPX2 showed significantly improved drought tolerance in seedlings. In the field, the yield of the wild-type plant decreased by 60% under drought conditions compared with normal conditions. However, the transgenic line showed a yield loss of approximately 26%. The results demonstrated that marker-free transgenic lines significantly improved grain yield under drought-stressed conditions.
基金Sponsored by the National Natural Science Foundation of China(Grant Nos.61372074 and 91438101)the National High Technology Research and Development Program of China(Grant No.2015AA01A709)
文摘The girth plays an important role in the design of LDPC codes. In order to determine the girth of Tanner(5,7) quasi-cyclic( QC) LDPC codes with length 7p for p being a prime with the form 35 m + 1,the cycles of lengths 4,6,8,and 10 are analyzed. Then these cycles are classified into sixteen categories,each of which can be expressed as an ordered block sequence,or a certain type. It is also shown that the existence of these cycles is equal to polynomial equations over Fpwho has a 35th unit root. We check if these polynomial equations have a 35th unit root and obtain the girth values of Tanner(5,7) QC LDPC codes.
文摘To carry out curriculum ideological and political education is to thoroughly implement the whole staff,the whole process,and all-round education.Taking the environmental chemistry course as an example,it introduces the feasibility of developing ideological and political education,and analyzes how to realize the integration of environmental chemistry courses and ideological and political education from the aspects of changing concepts,carefully designing teaching content,and playing the role of training courses and experimental courses.Integration has achieved certain results,providing reference and reference for environmental majors to carry out related courses ideological and political education.
基金supported by grants from the Tianjin Health Science and Technology Project(No.TJWJ2022MS001)Clinical research project of Tianjin Society of Hematology and Regenerative Medicine(No.2022 TSHRM08004)+3 种基金Key Project of Tianjin Natural Science Foundation(No.20JCZDJC00410)CAMS Innovation Fund for Medical Sciences(No.2021-I2M-1-073)Haihe Laboratory of Cell Ecosystem Innovation Fund(No.22HHXBSS00034)National Natural Science Foundation of China(Nos.82070192,8230012348,and 82170217)
文摘To the Editor:Allogeneic hemopoietic stem cell transplantation(allo-HSCT)represents the only long-term survival treatment choice for patients with myelodysplastic syndromes(MDS)and MDS/myeloproliferative neoplasm(MPN).Unfortunately,post-hemopoietic stem cell transplantation(HSCT)relapse remains a cause of treatment failure and the results of salvage treatments are poor.Developing better conditioning regimens is urgently needed.Previous studies have shown synergistic antileukemic effects between decitabine(DEC)and idarubicin(IDA).[1]In an attempt to design a conditioning strategy with very low toxicity but considerable myelosuppressive activity and potential immune-enhancing effects for patients with high-risk MDS and MDS/MPN,we combined DEC and IDA with busulfan,cyclophosphamide,andudarabine for a modied myeloablative regimen in this prospective,multicenter cohort study(hereafter referred to as the“DEC/IDA study”).
基金supported by the National Natural Science Foundation of China(Grant Nos.61832020,61821003 and U1705261)National Defense Preliminary Research Project(No.31511010202)+3 种基金the Fundamental Research Funds for the Central Universities,the Open Project Program of Wuhan National Laboratory for Optoelectronics(No.2022WNLOKF017)the Natural Science Foundation of Fujian Province(No.2020J01493)Zhejiang provincial“Ten Thousand Talents Program”(No.2021R52007)Center-initiated Research Project of Zhejiang Lab(No.2021DA0AM01).
文摘In order to analyze and process the large graphs with high cost efficiency,researchers have developed a number of out-of-core graph processing systems in recent years based on just one commodity computer.On the other hand,with the rapidly growing need of analyzing graphs in the real-world,graph processing systems have to efficiently handle massive concurrent graph processing(CGP)jobs.Unfortunately,due to the inherent design for single graph processing job,existing out-of-core graph processing systems usually incur unnecessary data accesses and severe competition of I/O bandwidth when handling the CGP jobs.In this paper,we propose GraphCP,a disk I/O optimized out-of-core graph processing system that efficiently supports the processing of CGP jobs.GraphCP proposes a benefit-aware sharing execution model to share the I/O access and processing of graph data among the CGP jobs and adaptively schedule the graph data loading based on the states of vertices,which efficiently overcomes above challenges faced by existing out-of-core graph processing systems.Moreover,GraphCP adopts a dependency-based future-vertex updating model so as to reduce disk I/Os in the future iterations.In addition,GraphCP organizes the graph data with a Source-Sorted Sub-Block graph representation for better processing capacity and I/O access locality.Extensive evaluation results show that GraphCP is 20.5×and 8.9×faster than two out-of-core graph processing systems GridGraph and GraphZ,and 3.5×and 1.7×faster than two state-of-art concurrent graph processing systems Seraph and GraphSO.
基金supported by the National Natural Science Foundation of China under Grant Nos.U22A2027,61832020,61832007,61821003the Science Technology and Innovation Commission of Shenzhen Municipality under Grant No.JCYJ20210324141601005the Henan Provincial Science and Technology Key Project Foundation under Grant Nos.212102310085,222102210054,222102210154,222102210252.
文摘Resistive random access memory(RRAM)enables the functionality of operating massively parallel dot products and accumulations.RRAM-based accelerator is such an effective approach to bridging the gap between Internet of Things devices’constrained resources and deep neural networks’tremendous cost.Due to the huge overhead of Analog to Digital(A/D)and digital accumulations,analog RRAM buffer is introduced to extend the processing in analog and in approximation.Although analog RRAM buffer offers potential solutions to A/D conversion issues,the energy consumption is still challenging in resource-constrained environments,especially with enormous intermediate data volume.Besides,critical concerns over endurance must also be resolved before the RRAM buffer could be frequently used in reality for DNN inference tasks.Then we propose LayCO,a layer-centric co-optimizing scheme to address the energy and endurance concerns altogether while strictly providing an inference accuracy guarantee.LayCO relies on two key ideas:1)co-optimizing with reduced supply voltage and reduced bit-width of accelerator architectures to increase the DNN’s error tolerance and achieve the accelerator’s energy efficiency,and 2)efficiently mapping and swapping individual DNN data to a corresponding RRAM partition in a way that meets the endurance requirements.The evaluation with representative DNN models demonstrates that LayCO outperforms the baseline RRAM buffer based accelerator by 27x improvement in energy efficiency(over TIMELY-like configuration),308x in lifetime prolongation and 6x in area reduction(over RAQ)while maintaining the DNN accuracy loss less than 1%.
文摘A storage system is the core of a computer,and plays an important role in the sustainable development of emerging strategic industries,such as artificial intelligence,big data,cloud computing,and the Internet of Things.Storage stack access is a major factor restricting the performance of data-intensive systems because of the increasing performance of processors and network devices.
