A PROCESS CONTROL SYSTEM WITH VF SR

Xu Dong,Chen Hongxin 전력전자학회 1995 ICPE(ISPE)논문집 Vol.1995 No.10

A frequency converter is used to build a linear closed-loop control system which can bo used to control the process parameters of object. It has the advantage of high efficiency and energy saving. Experiment result proves its effectiveness.

Somatic Embryogenesis from Various Parts of Muscari comosum var. plumosum

Xudong He,Ko Jeong-Ae,Choi Jeong-Ran,Kim Hyung-Moo,Kim Myung-Jun,Choi So-Ra,Kim Young-Gon,Kim Dong-Hee,Kim Hyun-Soon 한국자원식물학회 2006 한국자원식물학회지 Vol.19 No.3

In vitro high-frequency plant regeneration of Muscari comosum var. plumosum through somatic embryogenesis was obtained via two developmental pathways: direct embryos and multiple shoots regenerated from embryogenic callus. Flower bud with pedicel, receptacle, petal and ovary wall, floral stalk and leaf as explants were cultured in MS medium supplemented with various plant growth regulators. Embryos formed directly from pedicel, receptacle and floral stalk. Depending on explant sources, the optimal medium was MS medium supplemented with 0.2 mg/L IBA and 0.3 mg/L BA, 3.0 mg/L IBA and 3.0 mg/L BA, and MS-free medium for pedicel, receptacle, and floral stalk, respectively. Multiple shoots regenerated from embryogenic cal]i which was initiated from petal, ovary and leaf were observed in MS medium with different concentrations and combinations of hormone. The most suitable medium for each type of explant was 3.0 mg/L IBA and 3.0 mg/L BA(petal and ovary) and 5.0 mg/L IBA and 5.0 mg/L BA (leaf) Furthermore, the combination of 0.1 mg/L 2,4-D and 1.0 mg/L BA was also good for all sources of explants not only for direct embryo formation, but also, for embryogenic callus induction.

A numerical and theoretical investigation on composite pipe-in-pipe structure under impact

Xudong Qian,Yu Wang,J.Y. Richard Liew,Min-Hong Zhang 국제구조공학회 2016 Steel and Composite Structures, An International J Vol.22 No.5

This paper investigates the transverse impact response for ultra lightweight cement composite (ULCC) filled pipe-in-pipe structures through a parametric study using both a validated finite element procedure and a validated theoretical model. The parametric study explores the effect of the impact loading conditions (including the impact velocity and the indenter shape), the geometric properties (including the pipe length and the dimensions of the three material layers) as well as the material properties (including the material properties of the steel pipes and the filler materials) on the impact response of the pipe-in-pipe composite structures. The global impact responses predicted by the FE procedure and by the theoretical model agree with each other closely. The parametric study using the theoretical approach indicates the close relationships among the global impact responses (including the maximum impact force and the maximum global displacement) in specimens with the equivalent thicknesses, proposed in the theoretical model, for the pipe-in-pipe composite structures. In the pipe-in-pipe composite structure, the inner steel pipe, together with the outer steel pipe, imposes a strong confinement on the infilled cement composite and enhances significantly the composite action, leading to improved impact resistance, small global and local deformations.

Foreign Banks’ Entry and Local Banks’ Strategies in China

Xudong Chen,Liming Yao 한국증권학회 2017 Asia-Pacific Journal of Financial Studies Vol.46 No.4

The opening of the Chinese banking sector encourages the entry of foreign banks through greenfield investment or cooperation with local banks. The entry strategies of foreign banks are therefore influenced by the strategies of local banks. This paper examines the interaction between local and foreign banks. The results demonstrate that the superior capabilities of foreign banks to liquidate collateral facilitate their greenfield investment. Otherwise, foreign banks will cooperate with local banks, whose cooperation depends on local banks’ self-development capability. Our results suggest that foreign banks are more likely to cooperate with large local banks in China unless small local banks have greater self-development capabilities.

Pore Size Distribution of Cement Mortar Prepared with Crushed Limestone Sand

Xudong Chen,Shengxing Wu,Jikai Zhou 대한토목학회 2016 KSCE JOURNAL OF CIVIL ENGINEERING Vol.20 No.2

Recently, the use of crushed sand obtained from limestone-quarried is growing especially in the countries where river sand is not quite available. In the paper, the results from an experimental investigation are presented, which evaluates the pore structure of mortar mixtures where fine aggregate is replaced by Crushed Limestone Sand (CLS). The behavior of pore structure of CLS mortar was compared to that of mortars prepared from Nature River Sand (NRS). A Mercury Porosimeter Intrusion (MIP) is adopted to study the behavior of pore size distribution. Both CLS and NRS mortar with four water-cement ratios and five sand-cement ratios are used to determine pore structure. An analytical model was established to compare changes in pore structure for different water cement ratio and volume of sand, and the model was based on the test results.

Percutaneous endoscopic gastrostomy

Xudong Liu,Zhengqiang Yang,Shun He,Guiqi Wang 소화기인터벤션의학회 2021 Gastrointestinal Intervention Vol.10 No.2

Percutaneous endoscopic gastrostomy (PEG) is a feasible and safe technique for patients who need long-term feeding and cannot eat orally. With the increasing maturity of PEG technique, a large number of patients receive PEG tube placement every year in the world. However, PEG tube placement is not necessary in some patients, and some other patients are not evaluated strictly, leading to serious complications. In a broad sense, the mainly two indications for PEG include long-term enteral nutrition and gastric decompression. On the other hand, the main contraindications of PEG are distal intestinal obstruction, severe coagulation abnormalities, and severe infection at the PEG site. In the first section of this review, the indications and contraindications of PEG are introduced. Although PEG tube placement is a relatively safe technique, it can still cause a number of complications, including minor and major complications. Through standard management and treatment, the outcome of most patients is very good. In the second section of this review, we describe a variety of minor and major tube-related complications, and the treatment and prevention of these complications. In addition, the preparation and post-insertion care are also very important for PEG, which can reduce the incidence of complications. In the last section of this review, we describe related issues about the preparation and post-insertion care of PEG. In conclusion, PEG tube placement is a widely accepted technique that can bring benefits to the right patients.

Domain Adaption of Vehicle Detector based on Convolutional Neural Networks

Xudong Li,Mao Ye,Min Fu,Pei Xu,Tao Li 제어·로봇·시스템학회 2015 International Journal of Control, Automation, and Vol.13 No.4

Generally the performance of a vehicle detector will decrease rapidly, when it is trained on a fixed training set but applied to a specific scene with view changes. The reason is that in the training set only a few samples are helpful for vehicle detection in the specific scene while other samples disturb the accurate detections. To solve this problem, we propose a novel transfer learning method to adapt the trained vehicle detector based on convolutional neural networks (ConvNets) to a specific scene with several new labeled samples. At first we reserve the share-filters and update the non-shared filters to improve the sensitivity of the vehicles in the specific scene. Then we combine the similar feature maps to accelerate the detection speed. At last for making the vehicle detector stable, we fine-tune it several times with the updated training set. Our contributions are an original research on transferring the vehicle detector based on ConvNets and an optimization approach about removing the redundant connections in the ConvNet vehicle detector. The extensive comparative experiments on three different datasets demonstrate that the transferred detectors achieve the improvements on both of the accuracy and speed.

Coordination with Price Subsidy When Channels Compete in Real Estate Supply Chain

Xudong Liu 보안공학연구지원센터 2016 International Journal of u- and e- Service, Scienc Vol.9 No.11

With the expansion of real estate business, many real estate developers begin to sell some of their houses to some real estate agents and consumers buy those houses through real estate agent in China, which forms market competition with the direct sales channels that real estate developers establish. In order to obtain more profits, some real estate developers provide some real estate agents with price subsidy in the competitive sales channels. Therefore, pricing strategy and price subsidy level become key parameters of the developers’decision. By solving the realestate developer’s profit function, some key indexes in the centralized supply chain and those in the supply chain with the wholesale price contract are obtained. They include the retail price, the sales quantity in each sales channel, the price subsidy level and the total developer’s profit. The revenue-sharing contract is used to coordinate developer-dominant supply chain in decentralized decision. The results shows that the total profit of the real estate supply chain with the price subsidy is larger than that without the price subsidy and the revenue-sharing contract can coordinate the decentralized real estate supply chain. The optimal price subsidy decreases in the market scale that the real estate agent faces and the price subsidy will be canceled by the real estate developer when the market share the agent faces is fifty percent.

A Note on the Flexural Behavior of Concrete under Different Loading Rates

Xudong Chen,Jikai Zhou,Yuanyuan Yan 대한토목학회 2015 KSCE JOURNAL OF CIVIL ENGINEERING Vol.19 No.3

This paper examined the flexural behavior of large concrete specimens (300 × 300 × 1100 mm) under different strain rate. Fourstrain rates were examined: 10−6, 10−5, 10−4, and 10−3 s−1. The changes of flexural strength, dynamically increased factor, as well aselastic modulus in response to different strain rates were well addressed. The results show that increasing strain rate led to moreflattened surfaces of the specimens, In addition, more aggregates found to be broken on the fractured surface. The elastic modulusand flexural strength of the concrete were positively correlated to the strain rate. Nevertheless, the increase in elastic modulus wasapproximately half of the percentage of increase in flexural strength. There was no clear change for the Poisson’s ratio in response tothe change in strain rates.

Experimental Study and Constitutive Model on Complete Stress-strain Relations of Plain Concrete in Uniaxial Cyclic Tension

Xudong Chen,Lingyu Xu,Jingwu Bu 대한토목학회 2017 KSCE JOURNAL OF CIVIL ENGINEERING Vol.21 No.5

Due to the difficulties of testing concrete in direct uniaxial tension, only limited data are available. In this paper, the cyclic tensile test on the plain concrete was carried out. Based on the experimental data, the plasticity and damage evolution can be formulated with respect to elastic strain. A constitutive model for cyclic tensile behavior of concrete is proposed. The proposed model can describe the nonlinear post-peak performance of concrete in direct tension including hysteresis loops. Finally, a statistical damage model is derived to describe the microcrack growth of concrete under monotonic and cyclic tension loading. Results demonstrated that the microcracks growth of concrete under cyclic tension loading can be formulated by the Weibull cumulative distribution function.