A Formal Method of CPU Resources Scheduling in the Cloud Computing Environment

Xiaodong Liu,Huating Xu,Li He 보안공학연구지원센터 2015 International Journal of Grid and Distributed Comp Vol.8 No.1

In the virtualization based cloud computing environment, multiple computers are allowed to run as virtual machines (VM) in a single physical computer. Efficient scheduling of limited underlying resources has been a key issue. This paper presents a formal method of CPU resources scheduling (FRS). VMs are divided into three resources statuses according to resources requirements and their run information. FRS scheduling is formally scheduling CPU resources according to the resources statuses. The implementation of FRS is confined to the VMM layer, without VM dependency. The evaluation shows that idle CPU resources of VMs are be used by those VMs which need more CPU resources and the CPU resources overall utilization is improved.

Taxi Resource Allocation in the Era of “Internet+”

Xiaodong Xu 보안공학연구지원센터 2016 International Journal of Smart Home Vol.10 No.7

In view of the problem A, first based on a large number of analysis reports and our own understandings, we defined "supply and demand matching degree" as β value can be quantified and obtained. And then by looking up the related document literature, through summary can get five groups of operational indicators easy to be obtained from the data as: population density, travel frequency, the selected proportion of the taxi, starting price, average waiting time, and the different areas and different time of target data represent different space-time concept in problem A. In the five groups of indicators data of Beijing time 8:00 to be correlation analysis with β, further selected four groups of strong correlation major indicators as population density, travel frequency, selected taxi ratio, average waiting time; then using selected these four groups of main indicators and β to build multivariate linear regression model, and the regression equation between β and every indicator is obtained; in order to verify the rationality of the established regression equation, with Beijing time 22:00 four groups of indicators into the model, get a set of β predictive value, and the actual value of the β using Pearson correlation coefficient to analyze the correlation, found the correlation is stronger, shows that the established model with strong degree of coincidence of the actual situation; so it can use this model to analyze the influence of different space and time indictor on the matching of supply and demand. In view of the problem B, it requires to design a reasonable and effective subsidy scheme, and verify the rationality of the scheme. An effective and reasonable subsidy scheme can inevitably reduce the problem of "difficult to take a taxi", by searching data, found that the taxi daily total mileage is a certain value, so the taxi daily effective mileage, can directly affect the difficulty level of taking a taxi. So we reflect the difficulty level of taking a taxi by the daily effective mileage of the taxi, and take it as a goal, combined with Module of Preventing Increase for the establishment of the model, through choosing the middle variables such as orders, software market shares, the frequency of taking a taxi, etc., to establish the relation function between daily mileage of the taxi with subsidies amount. It can be found from the observation function images, with the increase of the subsidies amount, the daily effective mileage of a taxi shows the tendency of increase first then decrease. Through consulting data, we can regulate the effective mileage above 250 kilometers can ease the difficulty of taking a taxi at the greatest extent. Then substitute it into the known data, compared with data obtained from function, the difference of both is not large, then it can be concluded that the scheme is reasonable.

Freeze-dried WS2 composites with low content of graphene as high-rate lithium storage materials

Xu, Xiaodong,Rout, Chandra Sekhar,Yang, Jieun,Cao, Ruiguo,Oh, Pilgun,Shin, Hyeon Suk,Cho, Jaephil The Royal Society of Chemistry 2013 Journal of Materials Chemistry A Vol.1 No.46

China FuTURE 4G TDD System: TD-SCDMA Evolution

Xu Xiaodong,Tao Xiaofeng,Zhang Ping 에스케이텔레콤 (주) 2009 Telecommunications Review Vol.19 No.3

Meeting with the evolution requirements from 3G to 4G system, FuTURE project and FuTURE 4G TDD system are introduced in detail, including the features, the key technologies related with the cellular architecture, physical layer and the implementation of trial system. It has been proved by the field tests that the FuTURE TDD system that can achieve the peak data rate of 122Mbps, where many enhanced technologies comparing with TD-SCDMA are adopted, including the Generalized Distributed Network Architecture, Soft Fractional Frequency Reuse and Fast Cell Group Selection. Moreover, some technologies proposed in the research and development of FuTURE TDD system have been accepted by 3GPP and become the candidate standards of the Enhanced 3G systems. At last, Gbps TDD system is now under researching and developing in China aiming with ITU IMT-Advanced (4G) system.

Experimental and numerical study on mechanical behavior of RC shear walls with precast steel-concrete composite module in nuclear power plant

Xu Haitao,Xu Jinbin,Dong Zhanfa,Ding Zhixin,Bai Mingxin,Du Xiaodong,Wang Dayang 한국원자력학회 2024 Nuclear Engineering and Technology Vol.56 No.6

Reinforced concrete (RC) shear walls with precast steel-concrete composite modular (PSCCM) are strongly recommended in the structural design of nuclear power plants due to the need for a large number of process pipeline crossings and industrial construction. However, the effect of the PSCCM on the mechanical behavior of the whole RC shear wall is still unknown and has received little attention. In this study, three 1:3 scaled specimens, one traditional shear wall specimen (TW) and two shear wall specimens with the PSCCM (PW1, PW2), were designed and investigated under cyclic loadings. The failure mode, hysteretic curve, energy dissipation, stiffness and strength degradations were then comparatively investigated to reveal the effect of the PSCCM. Furthermore, numerical models of the RC shear wall with different PSCCM distributions were analyzed. The results show that the shear wall with the PSCCM has comparable mechanical properties with the traditional shear wall, which can be further improved by adding reinforced concrete constraints on both sides of the shear wall. The accumulated energy dissipation of the PW2 is higher than that of the TW and PW1 by 98.7 % and 60.0 %. The failure of the shear wall with the PSCCM is mainly concentrated in the reinforced concrete wall below the PSCCM, while the PSCCM maintains an elastic working state as a whole. Shear walls with the PSCCM arranged in the high stress zone will have a higher load-bearing capacity and lateral stiffness, but will suffer a higher risk of failure. The PSCCM in the low stress zone is always in an elastic working state.

A Workload-aware Resources Scheduling Method for Virtual Machine

Hongshan Qu,Xiaodong Liu,Huating Xu 보안공학연구지원센터 2015 International Journal of Grid and Distributed Comp Vol.8 No.1

Virtualization-based cloud computing platforms allow multiple virtual machines (VMs) running on the same physical machine. Efficient allocation of limited underlying resources has been a key issue. In order to improve the CPU resources utilization, this paper presents a workload-aware CPU resources scheduling method (WARS). WARS uses the allocated credits and consumed credits to diagnose the CPU resources requirements of VMs and dynamically adjusts CPU resources according to the requirements of VMs. The adjustment of CPU resources is converted into increased or decreased weights of VMs. The implementation of WARS is confined to the VMM layer, without VM dependency. Our evaluation shows that WARS can improve the overall utilization of CPU resources.

Formal Description of the Virtual Machines System Framework

Xiaodong Liu,Li He,Hating Xu 보안공학연구지원센터 2015 International Journal of Multimedia and Ubiquitous Vol.10 No.3

Virtual resources have the duality of hardware and software, which brings new challenges to virtual resources management and manipulation. There is urgent need for formally describing virtual resources in order to effectively reason about virtual resources allocation, scheduling and management. This paper describes the virtual resources and their dynamic behavior. We first give the formal definition of the resources pool and the virtual machine (VM). Then, we describe the dynamic behavior of VMs. In particular, we present a formal description of how virtual resources are used by VMs. This paper reveals the logical laws of virtual resources and their dynamic behaviors and makes the virtualization theory system more rigorous.

IL28B Is Associated with Outcomes of Chronic HBV Infection

Xiaodong Shi,Junqi Niu,Xiumei Chi,Yu Pan,Yanhang Gao,Wanyu Li,Chen Yang,Jin Zhong,Damo Xu,Manna Zhang,Gerald Minuk,Jing Jiang 연세대학교의과대학 2015 Yonsei medical journal Vol.56 No.3

Purpose: The role of IL28B gene variants and expression in hepatitis B virus (HBV) infections are not well understood. Here, we evaluated whether IL28B gene expression and rs12979860 variations are associated with HBV outcomes. Materialsand Methods: IL28B genetic variations (rs12979860) were genotyped by pyrosequencingof DNA samples from 137 individuals with chronic HBV infection [50 inactive carriers (IC), 34 chronic hepatitis B (CHB), 27 cirrhosis, 26 hepatocellular carcinoma (HCC)], and 19 healthy controls. IL28A/B mRNA expression in peripheralblood mononuclear cells was determined by qRT-PCR, and serum IL28B proteinwas measured by ELISA. Results: Patients with IL28B C/C genotype had greater IL28A/B mRNA expression and higher IL28B protein levels than C/T patients. Within the various disease stages, compared to IC and healthy controls, IL28B expression was reduced in the CHB, cirrhosis, and HCC cohorts (CHB vs. IC, p=0.02; cirrhosis vs. IC, p=0.01; HCC vs. IC, p=0.001; CHB vs. controls, p<0.01; cirrhosis vs. controls, p<0.01; HCC vs. controls, p<0.01). When stratified with respect to serum HBV markers in the IC and CHB cohorts, IL28B mRNA and protein levels were higher in HBeAg-positive than negative individuals (p=0.01). Logistic regression analysis revealed that factors associated with high IL28B proteinlevels were C/C versus C/T genotype [p=0.016, odds ratio (OR)=0.25, 95% confidence interval (CI)=0.08‒0.78], high alanine aminotransferase values (p<0.001, OR=8.02, 95% CI=2.64‒24.4), and the IC stage of HBV infection (p<0.001). Conclusion: Our data suggest that IL28B genetic variations may play an important role in long-term development of disease in chronic HBV infections.

Green algae dominance quickly switches to cyanobacteria dominance after nutrient enrichment in greenhouse with high temperature

Xiaodong Wang,Xingguo Liu1,Boqiang Qin,Zhaojun Gu,Hao Xu,Hao Zhu,Guofeng Cheng,Huang Liu 한국생태학회 2015 Journal of Ecology and Environment Vol.38 No.3

In order to understand the mechanisms of conversion between different algal dominance, an experiment was performed in a greenhouse from 22 June to 10 July 2011. The experiment included a treatment group subjected to three instances of nutrient enrichment and a control with no nutrient enrichment. The initial water was dominated by Ankistrodesmus of Chlorophyta. The average water temperature at 08:30 h and 14:00 h during the experiment was 31.6°C and 34.6°C, respec¬tively. The results showed that the total nitrogen (TN), total phosphorus (TP), dissolved total nitrogen (DTN), dissolved total phosphorus (DTP), and soluble reactive phosphorus (SRP) concentrations in the treatment were significantly higher than in the control (P < 0.05). However, the TN/TP and DTN/DTP in the control was higher than in the treatment (P < 0.05). The dominant algae in the control did not change during the experiment, while the dominant algae in the treat¬ment switched to Planktothrix of Cyanophyta on day 9. The chlorophyll a (Chl-a), wet weight of all algae, wet weight of Cyanophyta, and percentage of Cyanophyta in the control were all significantly lower than in the treatment (P < 0.05). Amounts of zooplankton, especially rotifers, were present at the end of the experimental period. The density of rotifers between the control and treatment was not significantly different (P > 0.05), while the copepod density in the treatment was higher than in the control (P < 0.05). We conclude that green algae dominance quickly switches to cyanobacteria dominance after nutrient enrichment in a greenhouse with elevated temperature

ADAPTIVE FEEDFORWARD CONTROL OF A STEER-BY-WIRE SYSTEM BY ONLINE PARAMETER ESTIMATOR

Xiaodong Wu,Mingming Zhang,Min Xu,Yo Kakogawa 한국자동차공학회 2018 International journal of automotive technology Vol.19 No.1

The tracking control of the steer-by-wire (SBW) system to achevie desired steering motion is the core issue for the design of algorithm. Most of model-based tracking control assumed the constant parameters without the consideration of dynamic characteristics. The external disturbances and model nonlinearities can bring uncertainties of the system parameters. To reduce the influence of parameter uncertainties, an online estimator by output error identification method is proposed to estimate the dynamic parameters of a SBW system. Meanwhile, the parameter gradient projection method is applied to eliminate the parameter drift, while a full order state observer is developed to weaken the effects of noise disturbance during the parameter identification. Since the sensitivity of parameter uncertainties for the feedforward control, the online estimator is incorporated into the control model and improve the controlled robustness. The proposed adaptive feedforward controller is conducted by the real-time experiments to show the tracking performance.