Ejector performance prediction at critical and subcritical operational modes

Li, Fenglei,Tian, Qi,Wu, Changzhi,Wang, Xiangyu,Lee, Jae-Myung Pergamon 2017 Applied thermal engineering Vol. No.

<P><B>Abstract</B></P> <P>Traditional ejector models are focusing on the ejector performance predictions at critical mode under design conditions. In reality, ejector systems cannot be operated under these conditions perfectly. Thus, the study of ejector performance at subcritical mode under off-design conditions is important. In this paper, novel models for ejector performance predictions at critical point and breakdown point are developed based on constant-pressure mixing and constant-pressure disturbing assumptions. Then, the two models are integrated as the model to predict ejector performance at critical and subcritical operational modes. In order to determine the ejector component efficiencies in the models, a novel concept, the effect of the change (EOC) of efficiency, is introduced to identify the efficiencies which affect ejector performance significantly. Then, the identified efficiencies are determined by sparsity-enhanced optimization method. The predicted results obtained by our model are much more accurate than those obtained by existing methods.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Novel models for ejector performance analysis at critical and breakdown points are developed. </LI> <LI> The models are integrated to predict ejector performance over entire operational range. </LI> <LI> An analysis method is developed for identifying the ejector component efficiencies. </LI> <LI> The performance prediction errors over entire operational range are within ±10%. </LI> </UL> </P>

Skewed Data Distribution for Active Storage Systems on Hybrid Servers

Xiangyu Li,Shuibing He,Xianbin Xu 보안공학연구지원센터 2016 International Journal of Grid and Distributed Comp Vol.9 No.5

With the popularity of new storage technologies, hybrid active storage system provides an efficient way to improve the performance of high-performance computing applications. However, current active storage efforts have neglected the storage performance gap between heterogeneous servers, largely affecting the overall system performance. In this paper, we propose SDD, a Skewed Data Distribution scheme for hybrid active storage systems. In contrast to traditional even data distribution schemes, SDD distribute data on servers with skewed amount of data based on their performance. We have implemented a prototype of our proposed data layout scheme in a parallel I/O system, and demonstrated its benefits with a typical data processing application. Experimental results show our proposed data placement scheme can significantly improve the overall active storage system performance.

A Distributed Implementation Algorithm for Physical Layer Security Based on Untrusted Relay Cooperation and Artificial Noise

Xiangyu Li,Xueming Wang,Xiangyang Xu,Liang Jin 한국전자통신연구원 2014 ETRI Journal Vol.36 No.1

In this letter, we consider a cooperation system with multipleuntrusted relays (URs). To keep the transmitted informationconfidential, we obtain joint channel characteristics (JCCs)through combining the channels from the source to thedestination. Then, in the null space of the JCCs, jammersconstruct artificial noise to confuse URs when the source nodebroadcasts its data. Through a distributed implementationalgorithm, the weight of each node can be obtained from itsown channel state information. Simulation results show thathigh-level security of the system can be achieved when internaland external eavesdroppers coexist.

Association analysis of polymorphism in the NR6A1 gene with the lumbar vertebrae number traits in sheep

Xiangyu Zhang,Cunyuan Li,Xiaoyue Li,Zhijin Liu,Wei Ni,Yang Cao,Yang Yao,Esenbay Islamov,Junchang Wei,Xiaoxu Hou,Shengwei Hu 한국유전학회 2019 Genes & Genomics Vol.41 No.10

Introduction The vertebral number is an economically significant trait, which is associated with body length and carcass traits. Nuclear Receptor Subfamily 6, Group A, Member 1 (NR6A1) is a member of the nuclear receptor superfamily and it plays an important role in the early development of embryos. Objectives The NR6A1 gene was considered as an important candidate for influence vertebrae number, while the potential associations between this gene and the number of lumbar vertebrae traits of sheep have not been explored. Methods In this study, we detected the genetic variants of NR6A1 gene and analyzed the associations of the polymorphisms with lumbar number traits in 130 Kazakh sheep. We use single-strand conformation polymorphism (SSCP) technique to detect single nucleotide polymorphism (SNP) of NR6A1 gene, and the association of the genotype and lumbar number variation was analyzed by independent Chi-square test. Results We detect SNP of NR6A1 gene by PCR-SSCP technique, and polymorphisms were only found in the coding region of exon-6 and exon-8 of NR6A1 gene. In order to investigate the connection between the SNP locus and lumbar number traits in sheep, we conducted a Chi-square test for independence for exon-6 and exon-8 of NR6A1 gene, respectively. Association analysis revealed significant associations between the SNP (rs414302710: A >C) in the exon-8 of NR6A1 gene with the number of lumbar vertebrae (P < 0.01). Conclusion Our study indicated that this SNP (rs414302710: A>C) locus of exon-8 of NR6A1 gene in sheep possible influence the number of lumbar vertebrae, which has the potential to be applied in selective breeding of sheep.

Incremental gradient-free method for nonsmooth distributed optimization

Li, Jueyou,Li, Guoquan,Wu, Zhiyou,Wu, Changzhi,Wang, Xiangyu,Lee, Jae-Myung,Jung, Kwang-Hyo AMERICAN INSTITUTE OF MATHEMATICAL SCIENCES 2017 JOURNAL OF INDUSTRIAL AND MANAGEMENT OPTIMIZATION Vol. No.

JAS : JVM-Based Active Storage Framework for Object-based Storage Systems

Xiangyu Li,Shuibing He,Xianbin Xu,Yang Wang 보안공학연구지원센터 2016 International Journal of Database Theory and Appli Vol.9 No.7

We propose JAS, a JVM-based active storage framework for object-based storage systems. JAS programs the active storage functions of users as Java codes, and allows them to be executed on different OSD platforms (Operating systems and hardware) without recompiling. JAS offloads the active storage code from a client to the OSD by extending the standard OSD command set, and execute the Java code on the OSD on-demand by triggering them through extended client interfaces. We have implemented JAS under an object-based storage system. Experimental results show that the JVM-based active storage framework has been successfully set up, and this cross-platform design can largely improve system performance.

Bond Behavior of Spiral Ribbed Ultra-high Strength Steel Rebar Embedded in Plain and Steel Fiber Reinforced High-Strength Concrete

Xiangyu Li,Jianwei Zhang,Juan Liu,Wanlin Cao 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.10

The bond behavior of spiral ribbed ultra-high strength (SRUHS) steel rebar embedded in plain high strength concrete (HSC) and steel fiber reinforced high strength concrete (SFRHSC) is experimentally studied using pull-out tests. The influencing factors of concrete type, embedded length, cover thickness and stirrup ratio are considered and the bond failure characteristics as well as the whole process of stress-slip behavior are analyzed. The research shows good anchorage ductility between SRUHS steel rebar and HSC. Since SRUHS steel rebars have continuous spiral bite teeth with concrete, the concrete in the rib dales is not easily sheared off, thereby leading to a reliable bond strength. Compared to specimens without steel fibers, steel fiber reinforcement can increase the ultimate bond strength, bond stiffness and residual strength. Meanwhile, it will also reduce the influence of cover thickness, stirrup ratio on the specimens with steel fibers. Finally, a prediction calculation for ultimate bond stress and an analytical model for bond stress-slip relation are proposed, which match well with test results.

Updated Bayesian Network Meta-Analysis of Adjuvant Targeted Treatment Regimens for Early Human Epidermal Growth Factor Receptor-2 Positive Breast Cancer

Xinyan Li,Litong Yao,Mozhi Wang,Mengshen Wang,Xiang Li,Xueting Yu,Jingyi Guo,Haoran Dong,Xiangyu Sun,Yingying Xu 한국유방암학회 2020 Journal of breast cancer Vol.23 No.4

Purpose: Combining targeted agents with adjuvant chemotherapy prolongs survival in human epidermal growth factor receptor 2 (HER2)-positive breast cancer patients, but also increases the risk of adverse effects. The updated results of 3 randomized controlled trials (RCTs) were reported in 2019. Given the lack of adequate head-to-head pairwise assessment for anti-HER2 agents, network meta-analysis facilitates obtaining more precise inference for evidence-based therapy. Methods: RCTs comparing at least 2 anti-HER2 regimens in an adjuvant setting for HER2- positive early-stage breast cancer (EBC) were included. Hazard ratios for overall survival (OS) and disease free survival (DFS), with respective 95% confidence intervals were pooled for assessment of efficacy. A Bayesian statistical model was used, and odds ratios (ORs) for adverse events (AEs) were used to pool effect sizes. Results: We demonstrated that 1-year trastuzumab plus chemotherapy had increased efficacy compared to shorter or longer treatment duration. The OR of cardiac events gradually increased from 6 months to 1 and 2-year trastuzumab arms, relative to chemotherapy only. Compared to trastuzumab plus chemotherapy, dual HER2-targeting therapies increased DFS, especially for hormone receptor negative patients. Dual anti-HER2 blockade regimens revealed an increased probability of gastrointestinal reactions. As a second agent, pertuzumab showed significantly higher DFS and OS. Conclusion: We conclude that 1-year adjuvant trastuzumab should remain as the standard treatment for HER2-positive EBC patients, as it has greater efficacy and a manageable proportion of AEs. Clinical efficacy can be increased for hormone receptor-negative tumors by including a second HER2-targeted agent to the treatment regimen. For hormone receptor-positive cases with basal disease, it is acceptable to reduce the risk of cardiotoxicity by shortening the duration of trastuzumab.

Formation Mechanism and Adhesion Evaluation of Debris in Ti–6Al–4V Alloy Turning

Changping Li,Xiangyu Liu,Moran Xu,Jielin Chen,Shujian Li,Pengnan Li,Tae Jo Ko 한국정밀공학회 2023 International Journal of Precision Engineering and Vol.10 No.5

In this paper, the formation mechanism of adhered debris on the surface of turned titanium alloy was studied. The adhesion rate of debris was calculated and evaluated using image extraction technology. The effects of cutting parameters and cooling conditions on the debris adhesion rate were also studied. Moreover, the chip temperature and trajectory in the turning process are analyzed using a finite element simulation and a thermal camera. The results show that there are three primary sources of adhered debris: the adhesion of the built-up edge, the micro-chips formed during the cutting process, and the micro-chips generated by the friction between the chip and the machined surface. In addition, the cutting speed is also one of the most significant factors affecting the adhesion of debris. The debris adhesion rate drops significantly as the cutting speed decreases. It was also found that the coolant can effectively reduce the debris adhesion rate, and this effect is more evident at low feed rates.

Analysis on the temperature dependent electrical properties of graphene/ Al–ZnO Schottky contact

Yapeng Li,Yingfeng Li,Jianhua Zhang,Xiangyu Zou,Yongshan Wang 한국물리학회 2019 Current Applied Physics Vol.19 No.10

The electrical characteristics of the graphene/Al–ZnO schottky contact with the temperature of 180 K–300 K have been discussed in detail. Based on the TE model, the barrier height increased and the ideal factor decreased with the increasing of temperature from 180 K to 300 K, which can be interpreted by the lateral inhomogeneities of schottky barrier height. Combined with the single gauss distribution function of barrier height, the lateral inhomogeneities distribution of barrier height at the interface was confirmed. By DLTS measurement, one electron trap centers were observed at the interface.