Percutaneous endoscopic gastrostomy

Xudong Liu,Zhengqiang Yang,Shun He,Guiqi Wang 소화기인터벤션의학회 2021 International journal of gastrointestinal interven 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.

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.

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.

Experimental Study and Analytical Modeling on Fatigue Properties of Pervious Concrete Made with Natural and Recycled Aggregates

Xudong Chen,Dandan Shi,Nan Shen,Shengtao Li,Saisai Liu 한국콘크리트학회 2019 International Journal of Concrete Structures and M Vol.13 No.1

As a solid pollutant, the recycled aggregate can be reused to replace the natural aggregate to cast pervious concrete, promoting resource recycling and reducing environmental pollution. Pervious concrete is usually applied to transportation engineering as pavements and decks, which are often subjected to fatigue loads in service. Therefore, it is essential to investigate the fatigue mechanical properties of pervious concrete. In this study, four-point cyclic bending loading test of natural aggregate pervious concrete and recycled aggregate pervious concrete were conducted under four different stress levels. By analyzing the experimental results, the mechanical performances, including hysteresis curve characteristics, damping ratio, dynamic elastic modulus and cyclic strain, of two kinds of pervious concrete under cyclic loading were revealed. Based on the improved EPF model, the relationship between fracture parameters, plastic strain and unloading strain were obtained. Besides, the relationship between the loading cycles and the ratio of plastic strain to unloading strain was received according to fatigue testing data under different stress levels. Further, the simplified fatigue model of pervious concrete was proposed and the experimental data was fitted with the model results. The fitting result reached a good agreement.

Set-membership Estimation for Event-triggered 2-D Systems Based on Zonotopes

Xudong Wang,Guoqi Wang,Liu Yang,Jitao Li 제어·로봇·시스템학회 2024 International Journal of Control, Automation, and Vol.22 No.3

This article discusses the interval estimation for 2-D systems in Roesser model with amplitude-boundedenvironmental disturbance and measurement noise. To save the limited capacity of communication network, anevent-triggered communication strategy is adopted to reduce the amount of packets transmitted through the network. Considering the amplitude-bounded uncertainties, an observer design criterion with peak-to-peak norm boundis deduced to suppress the influence of uncertainties on estimation error. A zonotope-based interval estimation approach is derived such that the actual state of 2-D Roesser system is enclosed within the estimated intervals on thebasis of the obtained observer. Finally, a numerical example is presented to verify the effectiveness of the proposedalgorithm

A New Cassane-type Diterpene and Other Constituents from Caesalpinia minax

Liu, Huiling,Ma, Guoxu,Yuan, Jingquan,Tan, Xiaoming,Zheng, Qingxia,Sun, Zhaocui,Yang, Junshan,Xu, Xudong Korean Chemical Society 2013 Bulletin of the Korean Chemical Society Vol.34 No.5

Pretreatment of sweet sorghum bagasse by alkaline hydrogen peroxide for enhancing ethanol production

Xudong Li,Weixing Cao,Chen Sun,Jiangping Qiu,Ronghou Liu,Le Zhang 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.3

Effects of severe and mild alkaline hydrogen peroxide (AHP) pretreatment on ethanol production from sweet sorghum bagasse via pre-simultaneous saccharification fermentation, and the chemical structure changes of the substrates were investigated. The results showed that the bagasse pretreated by severe AHP could produce more ethanol than that of mild AHP. The maximum ethanol concentration of the bagasses from mild and severe AHP pretreatment with 8% bagasse loading was 7.642±0.140 g/L and 19.330±0.085 g/L, respectively. Moreover, the FTIR and NMR analysis illustrated that the molecule and surface structures of the pretreated bagasse were significantly changed compared with the control. The potential biomass energy production of the effluent from the pretreatment was also briefly discussed for future utilization of waste solution.The heat energy potentials of waste solution with severe and mild AHP pretreatment were 367.2 kJ/Leffluent and 327.6 kJ/Leffluent, respectively.

Study on the Study on the Technology Strategies of Local Automobile Firms in China

Xudong Gao,Xielin Liu 한국경제발전학회 2004 經濟發展硏究 Vol.10 No.2

이 논문에서 우리는 중국의 지역 자동차 회사의 경쟁력과 기술능력 개발에 미치는 서로 다른 기술 전략의 효과를 알아본다. 데이터는 기술 진략, 특히 생산기술 전략에 따라서, 지역 자동차 업체가 세 개의 그룹 즉, 수용 그룹, 개발 그룹, 수용-개발 그룹으로 나뉘어질 수 있음을 보여준다. 또한 데이터는 단기적으로, 수용 그룹과 수용-개발 그룹이 상단시장을 장악하고, 개발 그룹은 하단시장에서 강한 경쟁력이 있음을 보여준다. 또한, 데이터는 개발 그룹과 수용-개발 그룹은 기술능력을 개발시키기에 더 유리한 조건에 있음을 보여준다. 본 논문은 이론적, 정책적 시사점을 제시하고 끝맺는다. (JEL O14) In this study we explore the impact of different technology strategies on local automobile firms' competitiveness and technological capability development in China. The dataindicate that the local car makers can be divided into three groups according to their technology strategies, especially product technology strategies: the product-adopter, the product-developer, and the adopter developer. The data also show that in the short term the product-adopters and the adopter - developers are dominating the higher end of the market, but the product-developers are becoming strong competitiveness at the lower end market. The data also indicate that the product-developers and the adopter developers are bettered positioned to develop technological capabilities. The study ends with a discussion about the theoretical and policy implications.

Seismic Bearing Capacity of Stirp Footings with Modified Pseudo-dynamic Method

Xudong Kang,Jianqun Zhu,Lili Liu 대한토목학회 2024 KSCE Journal of Civil Engineering Vol.28 No.5

Current research has shown a nonlinear trend in the failure of soil, and the single tangent method is commonly adopted when coping with nonlinear problems of soil failure. However, the method equates a nonlinear criterion to an optimizable linear criterion, which may differ from the actual situation, resulting in conservative results. In this paper, two types of piece-wise log-spiral failure mechanisms for bearing capacity estimations, including symmetrical and unilateral mechanisms were proposed with the nonlinear Mohr-Coulomb criterion. The static bearing capacity of foundations was evaluated using the symmetric failure mechanism, while the seismic bearing capacity of foundations was evaluated adopting a modified pseudo-dynamic method based on the unilateral failure mechanism. The result shows that the bearing capacity calculated in the paper is smaller compared to the result using the linear Mohr-Coulomb criterion. For London clay, the static bearing capacity is reduced by about 45% at a foundation width equal to 1m. From the comparisons, it is found that the proposed approach of piece-wise log-spiral failure mechanism for bearing capacity estimation is effective. In addition, parametric studies show that the nonlinear parameters, the initial factor of seismic acceleration, the normalized frequency, and the damping ratio all have obvious effects on the seismic bearing capacity. A significant reduction in the seismic bearing capacity of the foundation occurs when the normalized frequency sH/Vs is equal to (0.5 + n) (n = 0, 1, 2, …). Considering that the approach proposed provides a strict upper bound to the bearing capacity, the result imparts confidence in the approach of analysis presented.

Low-Voltage and High-Current DC Output Realized by Multiple Power Cells Based on Deadbeat and Automatic Current Sharing Control

Liu, Jinfeng,Zhang, Yu,Wang, Xudong,IU, Herbert Ho-Ching The Korean Institute of Electrical Engineers 2017 Journal of Electrical Engineering & Technology Vol.8 No.1

This paper presents a synchronous generator with a distributed system of multiple parallel three-phase power cells. This generator can immediately output high DC. Each power cell comprises three-phase windings and a three-phase synchronous rectification bridge with a deadbeat control of load power feedforward, which can improve the characteristics of dynamic response and reflect the load variance in real time. Furthermore, each power cell works well independently and modularly using the method of automatic maximum current sharing. The simulation and experimental results for the distributed controller of multiple power cells demonstrate that the deadbeat control method can respond quickly and optimize the quality of the energy. Meanwhile, automatic maximum current sharing can realize the validity of current sharing among power cells.