In situ studies on the shrinkage and expansion of graphene nanopores under electron beam irradiation at temperatures in the range of 400-1200^ooC

Lu, N.,Wang, J.,Floresca, H.C.,Kim, M.J. Pergamon Press ; Elsevier Science Ltd 2012 Carbon Vol.50 No.8

We report in situ studies on the shrinkage and expansion of graphene nanopores under electron beam irradiation at temperatures of 400-1200<SUP>o</SUP>C using a thermal specimen holder in a transmission electron microscope. The shrinkage of nanopores of various sizes is observed. At all temperatures studied in the present work, nanopores with relatively small diameters could be fully closed. And at the low end of our temperature range, 400<SUP>o</SUP>C, larger nanopores (those with a diameter of 10nm) could also be closed completely. The nanopore shrinking process can be stopped by blocking the electron beam. We demonstrate an approach for tailoring the size of the graphene nanopore through a combination of electron beam irradiation and controlled heat.

『상한론(傷寒論)』육경지면설(六經地面說)에 관한 연구(硏究)

( Shang Han Lun ) 대한한의학원전학회(구 대한원전의사학회) 2013 대한한의학원전학회지 Vol.26 No.3

Objective : Zhang Zhong-jing`s Shang-Han-Lun is based on Six-channels system(六經) to classified a disease, but the notion of this seems to be a very various angles. Among them, Ke-qin(柯琴)`s Six-surface theory(六經地面說) is very clearly explained the notion of Six-channels system(六經) and it provide crucial clue to understanding a Shang-Han-Lun Method : I will try to describe the Six-surface theory(六經地面說) through the Ke-qin`s Shang-Han-Lun-Yi(傷寒論翼). At the core of this paper, The diaphragm is the most important criterion to understand a Six-channels system(六經), and it is based on the human body to divided into Yin-Yang(陰陽). Result : Ke-qin`s Six-surface theory(六經地面說) is connected with Meridian system(經絡), Viscera and Bowels(臟腑), and their functions. It is the concept of comprehensive to including those related were grouped into the surface. Conclusion : Six-surface(六經地面) is far beyond the simple concept of Meridian, and it include organization of pathology concepts carrying up to what happens on the human body caused by disease. We can see that Zhong-jing`s(仲景) medical treatment from syndrome differentiation(辨證) is associated with a holism(整體觀).

Resistance Reduction Scheme for Tower Grounding with Conductive Cement

Lun Li,Tian Xu,Pei Feng,Liu Xin,Jia Lulu,Deng Chenxing,Wang Xing,Lan Fen,Cheng Hongbo 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.3

The construction conditions of transmission lines are becoming more and more diffi cult. It is necessary to fi nd new ways to reduce the grounding resistance of poles and towers at high soil resistivity and small construction area. Conductive cement samples with graphite, stainless steel fi bers, and their mixtures as conductive phases materials were prepared, the resistivity, fl exural strength and compressive strength were tested, compared and analyzed. The graphite and stainless steel fi ber conductive cement with better comprehensive performance was selected out for tower grounding. The application schemes of conductive cement for tower grounding were designed and compared, the partial wrapping scheme was selected and its application methods under diff erent soil resistivity was analyzed. The analysis results can provide theoretical basis and guidance for the application of conductive cement in transmission tower grounding, the feasibility of scheme is proved by the fi eld application.

Modal parameter estimation of civil structures based on improved variational mode decomposition

Lun-hai Zhi,Feng Hu,Chunfeng Zhao,Jingfeng Wang 국제구조공학회 2021 Structural Engineering and Mechanics, An Int'l Jou Vol.79 No.6

This paper proposes an improved variational mode decomposition (IVMD) algorithm for structural modal parameter estimation based on non-stationary responses. In this improved VMD, the mean envelope entropy (MEE) and particle swarm optimization (PSO) are first employed to determine the optimal decomposition parameters for the subsequent VMD analysis. Then the VMD algorithm is used to decompose the non-stationary data into a number of intrinsic mode functions (IMFs). After obtaining the IMFs based on the IVMD, structural modal parameters such as natural frequencies and damping ratios of civil structures can be determined by using Natural Excitation Technique (NExT) and Direct Interpolating approach (DI). The feasibility and accuracy of the proposed procedure are evaluated by both numerical and full-scale examples. The natural frequencies and damping ratios are successfully identified from the vibration responses with high noise and nonstationary characteristics. The results of this study illustrate that the proposed procedure provides a powerful approach to identify the modal parameters of civil structures using non-stationary responses.

Energy-Saving Oriented On/Off Strategies in Heterogeneous Networks : an Asynchronous Approach with Dynamic Traffic Variations

( Lun Tang ),( Weili Wang ),( Qianbin Chen ) 한국인터넷정보학회 2018 KSII Transactions on Internet and Information Syst Vol.12 No.11

Recent works have validated the possibility of reducing the energy consumption in wireless heterogeneous networks, achieved by switching on/off some base stations (BSs) dynamically. In this paper, to realize energy conservation, the discrete time Markov Decision Process (DTMDP) is developed to match up the BS switching operations with the traffic load variations. Then, an asynchronous decision-making algorithm, which is based on the Bellman equation and the on/off priorities of the BSs, is firstly put forward and proved to be optimal in this paper. Through reducing the state and action space during one decision, the proposed asynchronous algorithm can avoid the “curse of dimensionality” occurred in DTMDP frequently. Finally, numerical simulations are conducted to validate the effectiveness and advantages of the proposed asynchronous on/off strategies.

Thanks a lot Sir for your kind intimation! Dr. Pithwa

Lunli Xie,Jun Zhu,Shunhong Luo,Yu Xie,Dan Pu 대한척추외과학회 2018 Asian Spine Journal Vol.12 No.1

We analyzed dose-dependent effects of vancomycin on wound infection bacteria and investigated the relationship between dose and microbial imbalances in patients treated with intrawound vancomycin powder during spine surgery. Numerous trials have confirmed that using intrawound vancomycin powder during spine surgery may decrease postoperative wound infection rates. However, potential risks include changes in wound infection bacteria, inhibition of bone fusion, and systemic toxicity. We searched PubMed for articles published since October 2016 with the following terms: “local vancomycin” or “intrawound vancomycin” or “intraoperative vancomycin” or “intrawound vancomycin” or “topical vancomycin” and “spinal surgery” or “spine surgery.” We also screened the reference lists of included articles for additional studies and extracted data related to dose, infecting bacteria, sample size, infection rate and types, location of spine surgery, and perioperative antibiotics used. Our review includes one prospective and nine retrospective studies. Overall, 1 or 2 g local vancomycin powder was used in 2,394 patients. Gram-negative bacteria were dominant in patients in whom 1 g vancomycin powder was used, whereas gram-positive bacteria were dominant in those in whom 2 g powder was used. The exact mechanism underlying this dose-dependent trend remains unclear, although it may be attributed to the pharmacological characteristics of vancomycin. The included studies showed that trends in infection bacteria may change after the use of topical vancomycin powder. In addition, the observed increase in gram-negative bacteria when intrawound vancomycin powder is used has generated considerable attention. The present results differ from previous results but do not provide additional information regarding vancomycin dose and microbial changes in infected wounds. Additional large randomized controlled trials are needed to determine the relationship between vancomycin dose and the types of wound infection bacteria in patients treated with intrawound vancomycin powder during spine surgery.

Evolution of craniofacial surgery

Lun-Jou Lo 대한두개안면성형외과학회 2022 Archives of Craniofacial Surgery Vol.23 No.1

A Study on the Recognition of Number Plate

Lun man Deng(등륜만),Jeong Young Song(송정영) 한국정보기술학회 2007 Proceedings of KIIT Conference Vol.2007 No.-

Along with the development of traffic and the quantitative rise of cars, the intelligent management of traffic and vehicle become more and more important, license plate automatic recognition system is an intelligent traffic management system, the system combined with automatic detection, image process, computer vision, and pattern recognition. In this paper, comprehensive compared former license plate character list to identify a technique, combine the knowledge that the color image and the pattern recognition, carry on analysis to argue to know a vehicle of different type to the background color, then carry on through the license plate structure to concretely identify. Make use of the symmetry of the numeral structure according to the characteristic of the block style numeral structure, the brush stroke characteristics(level,perpendicular,flection) and 5 level straight lines and numeral hand over some piece to carry on arguing to know to the block style numeral. According to block style the characteristic of the Korean word structure, the symmetry, horizontal sweep line, perpendicularity that makes useof the form of written structure scans line a Korean word to carry on arguing to know to the block style.

Wind load estimation of super-tall buildings based on response data

Lun-hai Zhi,Bo Chen,Ming-xin Fang 국제구조공학회 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.56 No.4

Modern super-tall buildings are more sensitive to strong winds. The evaluation of wind loads for the design of these buildings is of primary importance. A direct monitoring of wind forces acting on super-tall structures is quite difficult to be realized. Indirect measurements interpreted by inverse techniques are therefore favourable since dynamic response measurements are easier to be carried out. To this end, a Kalman filtering based inverse approach is developed in this study so as to estimate the wind loads on super-tall buildings based on limited structural responses. The optimum solution of Kalman filter gain by solving the Riccati equation is used to update the identification accuracy of external loads. The feasibility of the developed estimation method is investigated through the wind tunnel test of a typical super-tall building by using a Synchronous Multi-Pressure Scanning System. The effects of crucial factors such as the type of wind-induced response, the covariance matrix of noise, errors of structural modal parameters and levels of noise involved in the measurements on the wind load estimations are examined through detailed parametric study. The effects of the number of vibration modes on the identification quality are studied and discussed in detail. The made observations indicate that the proposed inverse approach is an effective tool for predicting the wind loads on super-tall buildings.

Backstepping Iterative Learning Control for Wiener System

Lun Zhai,Guohui Tian,Yan Li 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.2

In this paper, the iterative learning control (ILC) scheme combined with the backstepping controller is applied to the Wiener system, which is a typical nonlinear and non-Lipschitz one. The ILC scheme as a feed forward control can improve the convergence speed, and the perfect tracking can be achieved as the system is repeatable. The backstepping control is a feedback control which improves the robustness of the control system, especially for the existence of non-repeatable noises. The backstepping part also guarantees the asymptotic stability, which further improves the convergence speed. The design of backstepping controller is based on the error information in the current control process, and the Lyapunov method. The convergence condition is achieved and the convergence speed is analyzed as well. It can be seen that the combination of ILC scheme and backstepping method can improve the system performance to a large extant. Numerical simulations validate the above conclusions.