The Dynamic Replication Mechanism of HDFS Hot File based on Cloud Storage

Mingyong Li,Yan Ma,Meilian Chen 보안공학연구지원센터 2015 International Journal of Security and Its Applicat Vol.9 No.8

As an open source cloud storage scheme, HDFS is used by more and more large enterprises and researchers, and is actually applied to many cloud computing systems to deal with huge amounts of data. HDFS has many advantages, but there are some problems such as NameNode single point of failure, small file problem, hot issues, etc. For HDFS hot issues, this paper proposes a dynamic Replication mechanism of HDFS hot file based on cloud storage(HDFS-DRM). The mechanism includes a Replication of the dynamic adjustment mechanism and adding, deleting duplicate node selection mechanism in two parts, by increasing the NameNode, BlockMap parameters, it records the number of reading requests of each file in a certain period of time to decide whether to increase or decrease the number of copies. The mechanism presents a replica placement method based on stage historical information and node load and selects the appropriate node to add or delete copies of documents to improve the utilization efficiency of the data node storage space effectively. Experimental results show that, HDFS - DRM in hot files case, compared to native HDFS file system access latency is significantly reduced, HDFS-DRM can solve the hot issues successfully.

Predicting fatigue life for finite roller contacts based on a mixed EHL model using realistic surface roughness

Mingyong Liu,Chenhui Wu,Chunai Yan 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.7

Surface contact fatigue is a major failure mode of many mechanical components, such as various gear pairs, bearings, cam-follower systems, and so on. The present study aims to develop a fatigue life prediction approach for finite line contact model using machined surface topography. Based on the developed model, the effect of working conditions and lubrication parameters on the lubrication performance and fatigue life are investigated. The obtained results show that, by introducing the realistic roughness, the distribution of pressure, film thickness and stress field is significant fluctuations. Meanwhile, the location of maximum stress tends to move to subsurface. The effect of load on fatigue life is significant. Yet, the speed does not seem to have a great influence on the fatigue life in various load ranges. It is also indicated that the high ambient viscosity is beneficial to the lubrication performance and fatigue life.

Parametric studies of lubrication performance of a helical gear pair with non-Newtonian fluids

Mingyong Liu,Caichao Zhu,Hua iju Liu,Chenhui Wu 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.1

In this paper, Thermal elastohydrodynamic lubrication (TEHL) model of a helical gear pair is proposed to study contact performanceduring the whole meshing period. Effects of working conditions and design parameters on lubrication performance, i.e. film thickness,pressure, temperature, friction coefficient, etc. are investigated. Influence of thermal effect and non-Newtonian effect are evaluatedthrough a detailed study on three characteristic meshing positions. Results show that, the thermal effects and non-Newtonian fluid bothhave significant effects on the lubrication performance of the helical gear pair, especially in high speed, heavy load cases. The effects ofnormal pressure angle, helix angle and module on lubrication performance along the line of action are discussed.

Hyers-Ulam-Rassias stability of a system of first order linear recurrences

Mingyong Xu 대한수학회 2007 대한수학회보 Vol.44 No.4

In this paper we discuss the Hyers-Ulam-Rassias stability of asystem of rst order linear recurrences with variable coecients in Banachspaces. The concept of the Hyers-Ulam-Rassias stability originated fromTh. M. Rassias’ stability theorem that appeared in his paper: On thestability of the linear mapping in Banach spaces, Proc. Amer. Math.Soc. 72 (1978), 297--300. As an application, the Hyers-Ulam-Rassiasstability of ap-order linear recurrence with variable coecients is proved.

HYERS-ULAM-RASSIAS STABILITY OF A SYSTEM OF FIRST ORDER LINEAR RECURRENCES

Xu, Mingyong Korean Mathematical Society 2007 대한수학회보 Vol.44 No.4

In this paper we discuss the Hyers-Ulam-Rassias stability of a system of first order linear recurrences with variable coefficients in Banach spaces. The concept of the Hyers-Ulam-Rassias stability originated from Th. M. Rassias# stability theorem that appeared in his paper: On the stability of the linear mapping in Banach spaces, Proc. Amer. Math. Soc. 72 (1978), 297-300. As an application, the Hyers-Ulam-Rassias stability of a p-order linear recurrence with variable coefficients is proved.

Optimal Design of Central Drainage Ditch Buried Depth for Highway Tunnel in Seasonally Frozen Region

Yuanfu Zhou,Mingyong Li,Danfeng Zhang,Xiaoqing Suo,Xuefu Zhang,Ke Dong 대한토목학회 2022 KSCE Journal of Civil Engineering Vol.26 No.4

In seasonally frozen regions, the drainage ditch of highway tunnels is usually set below the maximum frost depth. Hence, the deeply buried drainage ditch is often used, which increases the cost, difficulty, and time of tunnel construction. And it affects the stability of the surrounding rock and the tunnel structure safety. To solve these difficulties, this study investigated the optimal design of buried depth of central drainage ditch by numerical simulation. Based on a tunnel in Northwest China, a transient heat transfer model, which involves heat conduction and phase transition, was established. Then, the influences of different water amounts and thermal insulation technologies on the minimum buried depth of central drainage ditch were investigated. The results indicate that the thermal insulation layer, regardless of whether it is an internal thermal insulation layer, external thermal insulation layer, or foam concrete backfilled in invert arch, can prevent the drainage ditch from freezing and increase its elevation. The findings of this study can be helpful in optimizing the buried depth, selecting reasonable thermal insulation technology for central drainage ditch in seasonally frozen regions.

SVQL: A SQL Extended Query Language for Video Databases

Chenglang Lu,Mingyong Liu,Zongda Wu 보안공학연구지원센터 2015 International Journal of Database Theory and Appli Vol.8 No.3

With the rapid increasing of video data, video queries are becoming increasingly important. To better describe users’ video query requirements, developing a functional video query language has become a promising and interesting task. In this paper, we present a novel query language called SVQL for video databases, which is developed based on an extension of the traditional database query language SQL. In SVQL, we remain the clear and concise grammatical framework of SQL, thereby making SVQL easy to learn and use for traditional users, i.e., making SVQL with a user-friendly interface. Moreover, we extend the WHERE clause of SQL to introduce new conditional expressions, such as variable declaration, structure specification, feature specification and spatial-temporal specification, thereby, making SVQL with powerful expressiveness. In this paper, we first present the formal definitions of SVQL and illustrate its basic query capabilities using examples. Then, we discuss the SVQL query processing techniques. Finally, we evaluate SVQL through the comparison with other existing video query languages, and the evaluation results demonstrate the practicality and effectiveness of our proposed query language for video databases

Robust Vehicle-Infrastructure Localization Using Factor Graph and Probability Data Association

Feihu Zhang,Mingyong Liu,Dhiraj Gulati,Alois Knoll 한국통신학회 2018 Journal of communications and networks Vol.20 No.4

This paper presents a robust graph-based optimizationframework for vehicle-infrastructure cooperative localization. Compared to the state-of-the-art approaches, the proposed solutionkeeps high performance in presence of unknown data associationenvironments. In this paper, the association probability of eachmeasurement is calculated, and then assigned to the correspondingedges on the graph, in which the nonlinear least square method isutilized to optimize the state. Thus the proposed approach presentsa robust framework in the presence of high association uncertaintyduring vehicle-infrastructure cooperative localization, in which thecorresponding weights from outliers are lower than the true vehicles. The experimental results demonstrate the good robustness insimulated data.

An Effective Method for Deproteinization of Bioactive Polysaccharides Extracted from Lingzhi (Ganoderma atrum)

Yi Chen,Mingyong Xie,Wenjuan Li,Hui Zhang,Shaoping Nie,Yuanxing Wang,Chang Li 한국식품과학회 2012 Food Science and Biotechnology Vol.21 No.1

Deproteinization procedure is a fundamental step for analyzing polysaccharide from natural plants. In this study, in the course of refining bioactive polysaccharides from lingzhi (Ganoderma atrum), an effective deproteinization method using lead acetate solution was established by comparing with other available methods. The percentages of deproteinization, polysaccharide loss, and its antioxidant activities loss were used as the index to evaluate and optimize the precipitation experimental conditions. The results showed that the modified method, precipitation with the addition of 0.4-0.52%(w/v) lead acetate, was superior to the others, as evidenced by the highest deproteinization efficiency (88%), as well as the lowest polysaccharide loss (17%). And notably its antioxidant activity also remained good (loss 15%). It provides a simple prefractionation step for the analysis of polysaccharide from natural plants. Polysaccharide isolated by this method is in the native state. Our method may offer a rapid method for removing protein from plant polysaccharides in large scale.

A Novel Control Algorithm for the Self-organized Fission Behavior of Flocking System with Time Delay

Panpan Yang,Mingyong Liu,Xiaokang Lei,Cheng Song 제어·로봇·시스템학회 2016 International Journal of Control, Automation, and Vol.14 No.4

This paper studies the self-organized fission control problem for flocking system with time delay. Bothconstant and time-varying time delay cases are considered. Firstly, a novel information coupling degree (ICD) basedfission control algorithm, which is able to split a coherent flock into multiple sub-groups under conflict externalstimuli, is proposed. Then, for the case of constant time delay, the sufficient conditions for the fission controlalgorithm is derived using Lyapunov-Razumikhin theorem. For the case of time-varying time delay, Lyapunov-Krasovskii functional method is adopted to obtain the sufficient conditions for the fission control algorithm in termsof linear matrix inequalities (LMIs). Finally, numerical simulations are provided to illustrate the effectiveness ofthe theoretical results.